Beam management and beam failure recovery in a radio system

ABSTRACT

A wireless device receives one or more radio resource control messages from a base station. The one or more radio resource control messages comprising configuration parameters of a cell for beam failure recovery. The configuration parameters indicate: a serving beam set, a plurality of candidate beam sets, and a monitoring priority of the plurality of candidate beam sets. A beam failure instance of the serving beam set is detected. In response to the detection, a first candidate beam set of the plurality of candidate beam sets is determined based on the monitoring priority. A candidate beam is selected from the first candidate beam set. A preamble associated with the candidate beam for the beam failure recovery is transmitted.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/787,906, filed Jan. 3, 2019, which is hereby incorporated by reference in its entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosure are described herein with reference to the drawings.

FIG. 1 is a diagram of an example RAN architecture as per an aspect of an embodiment of the present disclosure.

FIG. 2A is a diagram of an example user plane protocol stack as per an aspect of an embodiment of the present disclosure.

FIG. 2B is a diagram of an example control plane protocol stack as per an aspect of an embodiment of the present disclosure.

FIG. 3 is a diagram of an example wireless device and two base stations as per an aspect of an embodiment of the present disclosure.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplink and downlink signal transmission as per an aspect of an embodiment of the present disclosure.

FIG. 5A is a diagram of an example uplink channel mapping and example uplink physical signals as per an aspect of an embodiment of the present disclosure.

FIG. 5B is a diagram of an example downlink channel mapping and example downlink physical signals as per an aspect of an embodiment of the present disclosure.

FIG. 6 is a diagram depicting an example transmission time or reception time for a carrier as per an aspect of an embodiment of the present disclosure.

FIG. 7A and FIG. 7B are diagrams depicting example sets of OFDM subcarriers as per an aspect of an embodiment of the present disclosure.

FIG. 8 is a diagram depicting example OFDM radio resources as per an aspect of an embodiment of the present disclosure.

FIG. 9A is a diagram depicting an example CSI-RS and/or SS block transmission in a multi-beam system.

FIG. 9B is a diagram depicting an example downlink beam management procedure as per an aspect of an embodiment of the present disclosure.

FIG. 10 is an example diagram of configured BWPs as per an aspect of an embodiment of the present disclosure.

FIG. 11A, and FIG. 11B are diagrams of an example multi connectivity as per an aspect of an embodiment of the present disclosure.

FIG. 12 is a diagram of an example random access procedure as per an aspect of an embodiment of the present disclosure.

FIG. 13 is a structure of example MAC entities as per an aspect of an embodiment of the present disclosure.

FIG. 14 is a diagram of an example RAN architecture as per an aspect of an embodiment of the present disclosure.

FIG. 15 is a diagram of example RRC states as per an aspect of an embodiment of the present disclosure.

FIG. 16A, FIG. 16B and FIG. 16C are examples of MAC subheaders as per an aspect of an embodiment of the present disclosure.

FIG. 17A and FIG. 17B are examples of MAC PDUs as per an aspect of an embodiment of the present disclosure.

FIG. 18 is an example of LCIDs for DL-SCH as per an aspect of an embodiment of the present disclosure.

FIG. 19 is an example of LCIDs for UL-SCH as per an aspect of an embodiment of the present disclosure.

FIG. 20A is an example of an SCell Activation/Deactivation MAC CE of one octet as per an aspect of an embodiment of the present disclosure.

FIG. 20B is an example of an SCell Activation/Deactivation MAC CE of four octets as per an aspect of an embodiment of the present disclosure.

FIG. 21A is an example of an SCell hibernation MAC CE of one octet as per an aspect of an embodiment of the present disclosure.

FIG. 21B is an example of an SCell hibernation MAC CE of four octets as per an aspect of an embodiment of the present disclosure.

FIG. 21C is an example of MAC control elements for an SCell state transitions as per an aspect of an embodiment of the present disclosure.

FIG. 22 is an example of a signaling-based SCell state transition as per an aspect of an embodiment of the present disclosure.

FIG. 23 is an example of a timer-based SCell state transition as per an aspect of an embodiment of the present disclosure.

FIG. 24 is an example of CSI RS transmission with multiple beams as per an aspect of an embodiment of the present disclosure.

FIG. 25 is an example of various beam management procedures as per an aspect of an embodiment of the present disclosure.

FIG. 26A and FIG. 26B are examples of beam failures as per an aspect of an embodiment of the present disclosure.

FIG. 27 is an example of DCI formats as per an aspect of an embodiment of the present disclosure.

FIG. 28 is an example of BWP management on an SCell as per an aspect of an embodiment of the present disclosure.

FIG. 29 is an example of mapping of PUCCH resource as per an aspect of an embodiment of the present disclosure.

FIG. 30A, FIG. 30B and FIG. 30C are examples of SRS transmissions as per an aspect of an embodiment of the present disclosure.

FIG. 31 is an example of downlink beam failure recovery request procedure as per an aspect of an embodiment of the present disclosure.

FIG. 32 is an example of candidate beam blocking as per an aspect of an embodiment of the present disclosure.

FIG. 33 is an example of multiple candidate beam sets configuration as per an aspect of an embodiment of the present disclosure.

FIG. 34 is an example of a beam failure recovery procedure for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 35 is an example of a beam failure recovery flow chart for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 36 is an example of multiple candidate beam sets configuration as per an aspect of an embodiment of the present disclosure.

FIG. 37 is an example of a beam failure recovery procedure for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 38 is an example of a beam failure recovery flow chart for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 39 is an example of multiple candidate beam sets configuration as per an aspect of an embodiment of the present disclosure.

FIG. 40 is an example of a beam failure recovery procedure for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 41 is an example of a beam failure recovery flow chart for multiple candidate beam sets as per an aspect of an embodiment of the present disclosure.

FIG. 42 is a flow diagram of an aspect of an example embodiment of the present disclosure.

FIG. 43 is a flow diagram of an aspect of an example embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Example embodiments of the present disclosure enable beam failure recovery operations of a wireless device and/or a base station. Embodiments of the technology disclosed herein may be employed in the technical field of beam management and beam failure recovery for multiple antenna communication systems. More particularly, the embodiments of the technology disclosed herein may relate to a wireless device and/or a base station in a multiple antennas and/or multiple panels communication system.

The following Acronyms are used throughout the present disclosure:

-   -   3GPP 3rd Generation Partnership Project     -   5GC 5G Core Network     -   ACK Acknowledgement     -   AMF Access and Mobility Management Function     -   ARQ Automatic Repeat Request     -   AS Access Stratum     -   ASIC Application-Specific Integrated Circuit     -   BA Bandwidth Adaptation     -   BCCH Broadcast Control Channel     -   BCH Broadcast Channel     -   BPSK Binary Phase Shift Keying     -   BWP Bandwidth Part     -   CA Carrier Aggregation     -   CC Component Carrier     -   CCCH Common Control CHannel     -   CDMA Code Division Multiple Access     -   CN Core Network     -   CP Cyclic Prefix     -   CP-OFDM Cyclic Prefix-Orthogonal Frequency Division Multiplex     -   C-RNTI Cell-Radio Network Temporary Identifier     -   CS Configured Scheduling     -   CSI Channel State Information     -   CSI-RS Channel State Information-Reference Signal     -   CQI Channel Quality Indicator     -   CSS Common Search Space     -   CU Central Unit     -   DAI Downlink Assignment Index     -   DC Dual Connectivity     -   DCCH Dedicated Control Channel     -   DCI Downlink Control Information     -   DL Downlink     -   DL-SCH Downlink Shared CHannel     -   DM-RS DeModulation Reference Signal     -   DRB Data Radio Bearer     -   DRX Discontinuous Reception     -   DTCH Dedicated Traffic Channel     -   DU Distributed Unit     -   EPC Evolved Packet Core     -   E-UTRA Evolved UMTS Terrestrial Radio Access     -   E-UTRAN Evolved-Universal Terrestrial Radio Access Network     -   FDD Frequency Division Duplex     -   FPGA Field Programmable Gate Arrays     -   F1-C F1-Control plane     -   F1-U F1-User plane     -   gNB next generation Node B     -   HARQ Hybrid Automatic Repeat reQuest     -   HDL Hardware Description Languages     -   IE Information Element     -   IP Internet Protocol     -   LCID Logical Channel Identifier     -   LTE Long Term Evolution     -   MAC Media Access Control     -   MCG Master Cell Group     -   MCS Modulation and Coding Scheme     -   MeNB Master evolved Node B     -   MIB Master Information Block     -   MME Mobility Management Entity     -   MN Master Node     -   NACK Negative Acknowledgement     -   NAS Non-Access Stratum     -   NG CP Next Generation Control Plane     -   NGC Next Generation Core     -   NG-C NG-Control plane     -   ng-eNB next generation evolved Node B     -   NG-U NG-User plane     -   NR New Radio     -   NR MAC New Radio MAC     -   NR PDCP New Radio PDCP     -   NR PHY New Radio PHYsical     -   NR RLC New Radio RLC     -   NR RRC New Radio RRC     -   NSSAI Network Slice Selection Assistance Information     -   O&M Operation and Maintenance     -   OFDM orthogonal Frequency Division Multiplexing     -   PBCH Physical Broadcast CHannel     -   PCC Primary Component Carrier     -   PCCH Paging Control CHannel     -   PCell Primary Cell     -   PCH Paging CHannel     -   PDCCH Physical Downlink Control CHannel     -   PDCP Packet Data Convergence Protocol     -   PDSCH Physical Downlink Shared CHannel     -   PDU Protocol Data Unit     -   PHICH Physical HARQ Indicator CHannel     -   PHY PHYsical     -   PLMN Public Land Mobile Network     -   PMI Precoding Matrix Indicator     -   PRACH Physical Random Access CHannel     -   PRB Physical Resource Block     -   PSCell Primary Secondary Cell     -   PSS Primary Synchronization Signal     -   pTAG primary Timing Advance Group     -   PT-RS Phase Tracking Reference Signal     -   PUCCH Physical Uplink Control CHannel     -   PUSCH Physical Uplink Shared CHannel     -   QAM Quadrature Amplitude Modulation     -   QFI Quality of Service Indicator     -   QoS Quality of Service     -   QPSK Quadrature Phase Shift Keying     -   RA Random Access     -   RACH Random Access CHannel     -   RAN Radio Access Network     -   RAT Radio Access Technology     -   RA-RNTI Random Access-Radio Network Temporary Identifier     -   RB Resource Blocks     -   RBG Resource Block Groups     -   RI Rank indicator     -   RLC Radio Link Control     -   RLM Radio Link Monitoring     -   RNTI Radio Network Temporary Identifier     -   RRC Radio Resource Control     -   RRM Radio Resource Management     -   RS Reference Signal     -   RSRP Reference Signal Received Power     -   SCC Secondary Component Carrier     -   SCell Secondary Cell     -   SCG Secondary Cell Group     -   SC-FDMA Single Carrier-Frequency Division Multiple Access     -   SDAP Service Data Adaptation Protocol     -   SDU Service Data Unit     -   SeNB Secondary evolved Node B     -   SFN System Frame Number     -   S-GW Serving GateWay     -   SI System Information     -   SIB System Information Block     -   SMF Session Management Function     -   SN Secondary Node     -   SpCell Special Cell     -   SRB Signaling Radio Bearer     -   SRS Sounding Reference Signal     -   SS Synchronization Signal     -   SSS Secondary Synchronization Signal     -   sTAG secondary Timing Advance Group     -   TA Timing Advance     -   TAG Timing Advance Group     -   TAI Tracking Area Identifier     -   TAT Time Alignment Timer     -   TB Transport Block     -   TCI Transmission Configuration Indication     -   TC-RNTI Temporary Cell-Radio Network Temporary Identifier     -   TDD Time Division Duplex     -   TDMA Time Division Multiple Access     -   TRP Transmission Reception Point     -   TTI Transmission Time Interval     -   UCI Uplink Control Information     -   UE User Equipment     -   UL Uplink     -   UL-SCH Uplink Shared CHannel     -   UPF User Plane Function     -   UPGW User Plane Gateway     -   VHDL VHSIC Hardware Description Language     -   Xn-C Xn-Control plane     -   Xn-U Xn-User plane

Example embodiments of the disclosure may be implemented using various physical layer modulation and transmission mechanisms. Example transmission mechanisms may include, but not limited to: Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Time Division Multiple Access (TDMA), Wavelet technologies, and/or the like. Hybrid transmission mechanisms such as TDMA/CDMA, and OFDM/CDMA may also be employed. Various modulation schemes may be applied for signal transmission in the physical layer. Examples of modulation schemes include, but are not limited to: phase, amplitude, code, a combination of these, and/or the like. An example radio transmission method may implement Quadrature Amplitude Modulation (QAM) using Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and/or the like. Physical radio transmission may be enhanced by dynamically or semi-dynamically changing the modulation and coding scheme depending on transmission requirements and radio conditions.

FIG. 1 is an example Radio Access Network (RAN) architecture as per an aspect of an embodiment of the present disclosure. As illustrated in this example, a RAN node may be a next generation Node B (gNB) (e.g. 120A, 120B) providing New Radio (NR) user plane and control plane protocol terminations towards a first wireless device (e.g. 110A). In an example, a RAN node may be a next generation evolved Node B (ng-eNB) (e.g. 120C, 120D), providing Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations towards a second wireless device (e.g. 110B). The first wireless device may communicate with a gNB over a Uu interface. The second wireless device may communicate with a ng-eNB over a Uu interface.

A gNB or an ng-eNB may host functions such as radio resource management and scheduling, IP header compression, encryption and integrity protection of data, selection of Access and Mobility Management Function (AMF) at User Equipment (UE) attachment, routing of user plane and control plane data, connection setup and release, scheduling and transmission of paging messages (originated from the AMF), scheduling and transmission of system broadcast information (originated from the AMF or Operation and Maintenance (O&M)), measurement and measurement reporting configuration, transport level packet marking in the uplink, session management, support of network slicing, Quality of Service (QoS) flow management and mapping to data radio bearers, support of UEs in RRC_INACTIVE state, distribution function for Non-Access Stratum (NAS) messages, RAN sharing, dual connectivity or tight interworking between NR and E-UTRA.

In an example, one or more gNBs and/or one or more ng-eNBs may be interconnected with each other by means of Xn interface. A gNB or an ng-eNB may be connected by means of NG interfaces to 5G Core Network (5GC). In an example, 5GC may comprise one or more AMF/User Plan Function (UPF) functions (e.g. 130A or 130B). A gNB or an ng-eNB may be connected to a UPF by means of an NG-User plane (NG-U) interface. The NG-U interface may provide delivery (e.g. non-guaranteed delivery) of user plane Protocol Data Units (PDUs) between a RAN node and the UPF. A gNB or an ng-eNB may be connected to an AMF by means of an NG-Control plane (NG-C) interface. The NG-C interface may provide functions such as NG interface management, UE context management, UE mobility management, transport of NAS messages, paging, PDU session management, configuration transfer or warning message transmission.

In an example, a UPF may host functions such as anchor point for intra-/inter-Radio Access Technology (RAT) mobility (when applicable), external PDU session point of interconnect to data network, packet routing and forwarding, packet inspection and user plane part of policy rule enforcement, traffic usage reporting, uplink classifier to support routing traffic flows to a data network, branching point to support multi-homed PDU session, QoS handling for user plane, e.g. packet filtering, gating, Uplink (UL)/Downlink (DL) rate enforcement, uplink traffic verification (e.g. Service Data Flow (SDF) to QoS flow mapping), downlink packet buffering and/or downlink data notification triggering.

In an example, an AMF may host functions such as NAS signaling termination, NAS signaling security, Access Stratum (AS) security control, inter Core Network (CN) node signaling for mobility between 3^(rd) Generation Partnership Project (3GPP) access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, support of intra-system and inter-system mobility, access authentication, access authorization including check of roaming rights, mobility management control (subscription and policies), support of network slicing and/or Session Management Function (SMF) selection.

FIG. 2A is an example user plane protocol stack, where Service Data Adaptation Protocol (SDAP) (e.g. 211 and 221), Packet Data Convergence Protocol (PDCP) (e.g. 212 and 222), Radio Link Control (RLC) (e.g. 213 and 223) and Media Access Control (MAC) (e.g. 214 and 224) sublayers and Physical (PHY) (e.g. 215 and 225) layer may be terminated in wireless device (e.g. 110) and gNB (e.g. 120) on the network side. In an example, a PHY layer provides transport services to higher layers (e.g. MAC, RRC, etc.). In an example, services and functions of a MAC sublayer may comprise mapping between logical channels and transport channels, multiplexing/demultiplexing of MAC Service Data Units (SDUs) belonging to one or different logical channels into/from Transport Blocks (TBs) delivered to/from the PHY layer, scheduling information reporting, error correction through Hybrid Automatic Repeat request (HARQ) (e.g. one HARQ entity per carrier in case of Carrier Aggregation (CA)), priority handling between UEs by means of dynamic scheduling, priority handling between logical channels of one UE by means of logical channel prioritization, and/or padding. A MAC entity may support one or multiple numerologies and/or transmission timings. In an example, mapping restrictions in a logical channel prioritization may control which numerology and/or transmission timing a logical channel may use. In an example, an RLC sublayer may supports transparent mode (TM), unacknowledged mode (UM) and acknowledged mode (AM) transmission modes. The RLC configuration may be per logical channel with no dependency on numerologies and/or Transmission Time Interval (TTI) durations. In an example, Automatic Repeat Request (ARQ) may operate on any of the numerologies and/or TTI durations the logical channel is configured with. In an example, services and functions of the PDCP layer for the user plane may comprise sequence numbering, header compression and decompression, transfer of user data, reordering and duplicate detection, PDCP PDU routing (e.g. in case of split bearers), retransmission of PDCP SDUs, ciphering, deciphering and integrity protection, PDCP SDU discard, PDCP re-establishment and data recovery for RLC AM, and/or duplication of PDCP PDUs. In an example, services and functions of SDAP may comprise mapping between a QoS flow and a data radio bearer. In an example, services and functions of SDAP may comprise mapping Quality of Service Indicator (QFI) in DL and UL packets. In an example, a protocol entity of SDAP may be configured for an individual PDU session.

FIG. 2B is an example control plane protocol stack where PDCP (e.g. 233 and 242), RLC (e.g. 234 and 243) and MAC (e.g. 235 and 244) sublayers and PHY (e.g. 236 and 245) layer may be terminated in wireless device (e.g. 110) and gNB (e.g. 120) on a network side and perform service and functions described above. In an example, RRC (e.g. 232 and 241) may be terminated in a wireless device and a gNB on a network side. In an example, services and functions of RRC may comprise broadcast of system information related to AS and NAS, paging initiated by 5GC or RAN, establishment, maintenance and release of an RRC connection between the UE and RAN, security functions including key management, establishment, configuration, maintenance and release of Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs), mobility functions, QoS management functions, UE measurement reporting and control of the reporting, detection of and recovery from radio link failure, and/or NAS message transfer to/from NAS from/to a UE. In an example, NAS control protocol (e.g. 231 and 251) may be terminated in the wireless device and AMF (e.g. 130) on a network side and may perform functions such as authentication, mobility management between a UE and a AMF for 3GPP access and non-3GPP access, and session management between a UE and a SMF for 3GPP access and non-3GPP access.

In an example, a base station may configure a plurality of logical channels for a wireless device. A logical channel in the plurality of logical channels may correspond to a radio bearer and the radio bearer may be associated with a QoS requirement. In an example, a base station may configure a logical channel to be mapped to one or more TTIs/numerologies in a plurality of TTIs/numerologies. The wireless device may receive a Downlink Control Information (DCI) via Physical Downlink Control CHannel (PDCCH) indicating an uplink grant. In an example, the uplink grant may be for a first TTI/numerology and may indicate uplink resources for transmission of a transport block. The base station may configure each logical channel in the plurality of logical channels with one or more parameters to be used by a logical channel prioritization procedure at the MAC layer of the wireless device. The one or more parameters may comprise priority, prioritized bit rate, etc. A logical channel in the plurality of logical channels may correspond to one or more buffers comprising data associated with the logical channel. The logical channel prioritization procedure may allocate the uplink resources to one or more first logical channels in the plurality of logical channels and/or one or more MAC Control Elements (CEs). The one or more first logical channels may be mapped to the first TTI/numerology. The MAC layer at the wireless device may multiplex one or more MAC CEs and/or one or more MAC SDUs (e.g., logical channel) in a MAC PDU (e.g., transport block). In an example, the MAC PDU may comprise a MAC header comprising a plurality of MAC sub-headers. A MAC sub-header in the plurality of MAC sub-headers may correspond to a MAC CE or a MAC SUD (logical channel) in the one or more MAC CEs and/or one or more MAC SDUs. In an example, a MAC CE or a logical channel may be configured with a Logical Channel IDentifier (LCID). In an example, LCID for a logical channel or a MAC CE may be fixed/pre-configured. In an example, LCID for a logical channel or MAC CE may be configured for the wireless device by the base station. The MAC sub-header corresponding to a MAC CE or a MAC SDU may comprise LCID associated with the MAC CE or the MAC SDU.

In an example, a base station may activate and/or deactivate and/or impact one or more processes (e.g., set values of one or more parameters of the one or more processes or start and/or stop one or more timers of the one or more processes) at the wireless device by employing one or more MAC commands. The one or more MAC commands may comprise one or more MAC control elements. In an example, the one or more processes may comprise activation and/or deactivation of PDCP packet duplication for one or more radio bearers. The base station may transmit a MAC CE comprising one or more fields, the values of the fields indicating activation and/or deactivation of PDCP duplication for the one or more radio bearers. In an example, the one or more processes may comprise Channel State Information (CSI) transmission of on one or more cells. The base station may transmit one or more MAC CEs indicating activation and/or deactivation of the CSI transmission on the one or more cells. In an example, the one or more processes may comprise activation or deactivation of one or more secondary cells. In an example, the base station may transmit a MA CE indicating activation or deactivation of one or more secondary cells. In an example, the base station may transmit one or more MAC CEs indicating starting and/or stopping one or more Discontinuous Reception (DRX) timers at the wireless device. In an example, the base station may transmit one or more MAC CEs indicating one or more timing advance values for one or more Timing Advance Groups (TAGs).

FIG. 3 is a block diagram of base stations (base station 1, 120A, and base station 2, 120B) and a wireless device 110. A wireless device may be called an UE. A base station may be called a NB, eNB, gNB, and/or ng-eNB. In an example, a wireless device and/or a base station may act as a relay node. The base station 1, 120A, may comprise at least one communication interface 320A (e.g. a wireless modem, an antenna, a wired modem, and/or the like), at least one processor 321A, and at least one set of program code instructions 323A stored in non-transitory memory 322A and executable by the at least one processor 321A. The base station 2, 120B, may comprise at least one communication interface 320B, at least one processor 321B, and at least one set of program code instructions 323B stored in non-transitory memory 322B and executable by the at least one processor 321B.

A base station may comprise many sectors for example: 1, 2, 3, 4, or 6 sectors. A base station may comprise many cells, for example, ranging from 1 to 50 cells or more. A cell may be categorized, for example, as a primary cell or secondary cell. At Radio Resource Control (RRC) connection establishment/re-establishment/handover, one serving cell may provide the NAS (non-access stratum) mobility information (e.g. Tracking Area Identifier (TAI)). At RRC connection re-establishment/handover, one serving cell may provide the security input. This cell may be referred to as the Primary Cell (PCell). In the downlink, a carrier corresponding to the PCell may be a DL Primary Component Carrier (PCC), while in the uplink, a carrier may be an UL PCC. Depending on wireless device capabilities, Secondary Cells (SCells) may be configured to form together with a PCell a set of serving cells. In a downlink, a carrier corresponding to an SCell may be a downlink secondary component carrier (DL SCC), while in an uplink, a carrier may be an uplink secondary component carrier (UL SCC). An SCell may or may not have an uplink carrier.

A cell, comprising a downlink carrier and optionally an uplink carrier, may be assigned a physical cell ID and a cell index. A carrier (downlink or uplink) may belong to one cell. The cell ID or cell index may also identify the downlink carrier or uplink carrier of the cell (depending on the context it is used). In the disclosure, a cell ID may be equally referred to a carrier ID, and a cell index may be referred to a carrier index. In an implementation, a physical cell ID or a cell index may be assigned to a cell. A cell ID may be determined using a synchronization signal transmitted on a downlink carrier. A cell index may be determined using RRC messages. For example, when the disclosure refers to a first physical cell ID for a first downlink carrier, the disclosure may mean the first physical cell ID is for a cell comprising the first downlink carrier. The same concept may apply to, for example, carrier activation. When the disclosure indicates that a first carrier is activated, the specification may equally mean that a cell comprising the first carrier is activated.

A base station may transmit to a wireless device one or more messages (e.g. RRC messages) comprising a plurality of configuration parameters for one or more cells. One or more cells may comprise at least one primary cell and at least one secondary cell. In an example, an RRC message may be broadcasted or unicasted to the wireless device. In an example, configuration parameters may comprise common parameters and dedicated parameters.

Services and/or functions of an RRC sublayer may comprise at least one of: broadcast of system information related to AS and NAS; paging initiated by 5GC and/or NG-RAN; establishment, maintenance, and/or release of an RRC connection between a wireless device and NG-RAN, which may comprise at least one of addition, modification and release of carrier aggregation; or addition, modification, and/or release of dual connectivity in NR or between E-UTRA and NR. Services and/or functions of an RRC sublayer may further comprise at least one of security functions comprising key management; establishment, configuration, maintenance, and/or release of Signaling Radio Bearers (SRBs) and/or Data Radio Bearers (DRBs); mobility functions which may comprise at least one of a handover (e.g. intra NR mobility or inter-RAT mobility) and a context transfer; or a wireless device cell selection and reselection and control of cell selection and reselection. Services and/or functions of an RRC sublayer may further comprise at least one of QoS management functions; a wireless device measurement configuration/reporting; detection of and/or recovery from radio link failure; or NAS message transfer to/from a core network entity (e.g. AMF, Mobility Management Entity (MME)) from/to the wireless device.

An RRC sublayer may support an RRC_Idle state, an RRC_Inactive state and/or an RRC_Connected state for a wireless device. In an RRC_Idle state, a wireless device may perform at least one of: Public Land Mobile Network (PLMN) selection; receiving broadcasted system information; cell selection/re-selection; monitoring/receiving a paging for mobile terminated data initiated by 5GC; paging for mobile terminated data area managed by 5GC; or DRX for CN paging configured via NAS. In an RRC_Inactive state, a wireless device may perform at least one of: receiving broadcasted system information; cell selection/re-selection; monitoring/receiving a RAN/CN paging initiated by NG-RAN/5GC; RAN-based notification area (RNA) managed by NG-RAN; or DRX for RAN/CN paging configured by NG-RAN/NAS. In an RRC_Idle state of a wireless device, a base station (e.g. NG-RAN) may keep a 5GC-NG-RAN connection (both C/U-planes) for the wireless device; and/or store a UE AS context for the wireless device. In an RRC_Connected state of a wireless device, a base station (e.g. NG-RAN) may perform at least one of: establishment of 5GC-NG-RAN connection (both C/U-planes) for the wireless device; storing a UE AS context for the wireless device; transmit/receive of unicast data to/from the wireless device; or network-controlled mobility based on measurement results received from the wireless device. In an RRC_Connected state of a wireless device, an NG-RAN may know a cell that the wireless device belongs to.

System information (SI) may be divided into minimum SI and other SI. The minimum SI may be periodically broadcast. The minimum SI may comprise basic information required for initial access and information for acquiring any other SI broadcast periodically or provisioned on-demand, i.e. scheduling information. The other SI may either be broadcast, or be provisioned in a dedicated manner, either triggered by a network or upon request from a wireless device. A minimum SI may be transmitted via two different downlink channels using different messages (e.g. MasterInformationBlock and SystemInformationBlockType1). Another SI may be transmitted via SystemInformationBlockType2. For a wireless device in an RRC_Connected state, dedicated RRC signaling may be employed for the request and delivery of the other SI. For the wireless device in the RRC_Idle state and/or the RRC_Inactive state, the request may trigger a random-access procedure.

A wireless device may report its radio access capability information which may be static. A base station may request what capabilities for a wireless device to report based on band information. When allowed by a network, a temporary capability restriction request may be sent by the wireless device to signal the limited availability of some capabilities (e.g. due to hardware sharing, interference or overheating) to the base station. The base station may confirm or reject the request. The temporary capability restriction may be transparent to 5GC (e.g., static capabilities may be stored in 5GC).

When CA is configured, a wireless device may have an RRC connection with a network. At RRC connection establishment/re-establishment/handover procedure, one serving cell may provide NAS mobility information, and at RRC connection re-establishment/handover, one serving cell may provide a security input. This cell may be referred to as the PCell. Depending on the capabilities of the wireless device, SCells may be configured to form together with the PCell a set of serving cells. The configured set of serving cells for the wireless device may comprise one PCell and one or more SCells.

The reconfiguration, addition and removal of SCells may be performed by RRC. At intra-NR handover, RRC may also add, remove, or reconfigure SCells for usage with the target PCell. When adding a new SCell, dedicated RRC signaling may be employed to send all required system information of the SCell i.e. while in connected mode, wireless devices may not need to acquire broadcasted system information directly from the SCells.

The purpose of an RRC connection reconfiguration procedure may be to modify an RRC connection, (e.g. to establish, modify and/or release RBs, to perform handover, to setup, modify, and/or release measurements, to add, modify, and/or release SCells and cell groups). As part of the RRC connection reconfiguration procedure, NAS dedicated information may be transferred from the network to the wireless device. The RRCConnectionReconfiguration message may be a command to modify an RRC connection. It may convey information for measurement configuration, mobility control, radio resource configuration (e.g. RBs, MAC main configuration and physical channel configuration) comprising any associated dedicated NAS information and security configuration. If the received RRC Connection Reconfiguration message includes the sCellToReleaseList, the wireless device may perform an SCell release. If the received RRC Connection Reconfiguration message includes the sCellToAddModList, the wireless device may perform SCell additions or modification.

An RRC connection establishment (or reestablishment, resume) procedure may be to establish (or reestablish, resume) an RRC connection. an RRC connection establishment procedure may comprise SRB1 establishment. The RRC connection establishment procedure may be used to transfer the initial NAS dedicated information/message from a wireless device to E-UTRAN. The RRCConnectionReestablishment message may be used to re-establish SRB1.

A measurement report procedure may be to transfer measurement results from a wireless device to NG-RAN. The wireless device may initiate a measurement report procedure after successful security activation. A measurement report message may be employed to transmit measurement results.

The wireless device 110 may comprise at least one communication interface 310 (e.g. a wireless modem, an antenna, and/or the like), at least one processor 314, and at least one set of program code instructions 316 stored in non-transitory memory 315 and executable by the at least one processor 314. The wireless device 110 may further comprise at least one of at least one speaker/microphone 311, at least one keypad 312, at least one display/touchpad 313, at least one power source 317, at least one global positioning system (GPS) chipset 318, and other peripherals 319.

The processor 314 of the wireless device 110, the processor 321A of the base station 1 120A, and/or the processor 321B of the base station 2 120B may comprise at least one of a general-purpose processor, a digital signal processor (DSP), a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and/or other programmable logic device, discrete gate and/or transistor logic, discrete hardware components, and the like. The processor 314 of the wireless device 110, the processor 321A in base station 1 120A, and/or the processor 321B in base station 2 120B may perform at least one of signal coding/processing, data processing, power control, input/output processing, and/or any other functionality that may enable the wireless device 110, the base station 1 120A and/or the base station 2 120B to operate in a wireless environment.

The processor 314 of the wireless device 110 may be connected to the speaker/microphone 311, the keypad 312, and/or the display/touchpad 313. The processor 314 may receive user input data from and/or provide user output data to the speaker/microphone 311, the keypad 312, and/or the display/touchpad 313. The processor 314 in the wireless device 110 may receive power from the power source 317 and/or may be configured to distribute the power to the other components in the wireless device 110. The power source 317 may comprise at least one of one or more dry cell batteries, solar cells, fuel cells, and the like. The processor 314 may be connected to the GPS chipset 318. The GPS chipset 318 may be configured to provide geographic location information of the wireless device 110.

The processor 314 of the wireless device 110 may further be connected to other peripherals 319, which may comprise one or more software and/or hardware modules that provide additional features and/or functionalities. For example, the peripherals 319 may comprise at least one of an accelerometer, a satellite transceiver, a digital camera, a universal serial bus (USB) port, a hands-free headset, a frequency modulated (FM) radio unit, a media player, an Internet browser, and the like.

The communication interface 320A of the base station 1, 120A, and/or the communication interface 320B of the base station 2, 120B, may be configured to communicate with the communication interface 310 of the wireless device 110 via a wireless link 330A and/or a wireless link 330B respectively. In an example, the communication interface 320A of the base station 1, 120A, may communicate with the communication interface 320B of the base station 2 and other RAN and core network nodes.

The wireless link 330A and/or the wireless link 330B may comprise at least one of a bi-directional link and/or a directional link. The communication interface 310 of the wireless device 110 may be configured to communicate with the communication interface 320A of the base station 1 120A and/or with the communication interface 320B of the base station 2 120B. The base station 1 120A and the wireless device 110 and/or the base station 2 120B and the wireless device 110 may be configured to send and receive transport blocks via the wireless link 330A and/or via the wireless link 330B, respectively. The wireless link 330A and/or the wireless link 330B may employ at least one frequency carrier. According to some of various aspects of embodiments, transceiver(s) may be employed. A transceiver may be a device that comprises both a transmitter and a receiver. Transceivers may be employed in devices such as wireless devices, base stations, relay nodes, and/or the like. Example embodiments for radio technology implemented in the communication interface 310, 320A, 320B and the wireless link 330A, 330B are illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 4D, FIG. 6, FIG. 7A, FIG. 7B, FIG. 8, and associated text.

In an example, other nodes in a wireless network (e.g. AMF, UPF, SMF, etc.) may comprise one or more communication interfaces, one or more processors, and memory storing instructions.

A node (e.g. wireless device, base station, AMF, SMF, UPF, servers, switches, antennas, and/or the like) may comprise one or more processors, and memory storing instructions that when executed by the one or more processors causes the node to perform certain processes and/or functions. Example embodiments may enable operation of single-carrier and/or multi-carrier communications. Other example embodiments may comprise a non-transitory tangible computer readable media comprising instructions executable by one or more processors to cause operation of single-carrier and/or multi-carrier communications. Yet other example embodiments may comprise an article of manufacture that comprises a non-transitory tangible computer readable machine-accessible medium having instructions encoded thereon for enabling programmable hardware to cause a node to enable operation of single-carrier and/or multi-carrier communications. The node may include processors, memory, interfaces, and/or the like.

An interface may comprise at least one of a hardware interface, a firmware interface, a software interface, and/or a combination thereof. The hardware interface may comprise connectors, wires, electronic devices such as drivers, amplifiers, and/or the like. The software interface may comprise code stored in a memory device to implement protocol(s), protocol layers, communication drivers, device drivers, combinations thereof, and/or the like. The firmware interface may comprise a combination of embedded hardware and code stored in and/or in communication with a memory device to implement connections, electronic device operations, protocol(s), protocol layers, communication drivers, device drivers, hardware operations, combinations thereof, and/or the like.

FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D are example diagrams for uplink and downlink signal transmission as per an aspect of an embodiment of the present disclosure. FIG. 4A shows an example uplink transmitter for at least one physical channel. A baseband signal representing a physical uplink shared channel may perform one or more functions. The one or more functions may comprise at least one of: scrambling; modulation of scrambled bits to generate complex-valued symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of the complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generation of complex-valued time-domain Single Carrier-Frequency Division Multiple Access (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like. In an example, when transform precoding is enabled, a SC-FDMA signal for uplink transmission may be generated. In an example, when transform precoding is not enabled, an CP-OFDM signal for uplink transmission may be generated by FIG. 4A. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments.

An example structure for modulation and up-conversion to the carrier frequency of the complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and/or the complex-valued Physical Random Access CHannel (PRACH) baseband signal is shown in FIG. 4B. Filtering may be employed prior to transmission.

An example structure for downlink transmissions is shown in FIG. 4C. The baseband signal representing a downlink physical channel may perform one or more functions. The one or more functions may comprise: scrambling of coded bits in a codeword to be transmitted on a physical channel; modulation of scrambled bits to generate complex-valued modulation symbols; mapping of the complex-valued modulation symbols onto one or several transmission layers; precoding of the complex-valued modulation symbols on a layer for transmission on the antenna ports; mapping of complex-valued modulation symbols for an antenna port to resource elements; generation of complex-valued time-domain OFDM signal for an antenna port; and/or the like. These functions are illustrated as examples and it is anticipated that other mechanisms may be implemented in various embodiments.

In an example, a gNB may transmit a first symbol and a second symbol on an antenna port, to a wireless device. The wireless device may infer the channel (e.g., fading gain, multipath delay, etc.) for conveying the second symbol on the antenna port, from the channel for conveying the first symbol on the antenna port. In an example, a first antenna port and a second antenna port may be quasi co-located if one or more large-scale properties of the channel over which a first symbol on the first antenna port is conveyed may be inferred from the channel over which a second symbol on a second antenna port is conveyed. The one or more large-scale properties may comprise at least one of: delay spread; doppler spread; doppler shift; average gain; average delay; and/or spatial Receiving (Rx) parameters.

An example modulation and up-conversion to the carrier frequency of the complex-valued OFDM baseband signal for an antenna port is shown in FIG. 4D. Filtering may be employed prior to transmission.

FIG. 5A is a diagram of an example uplink channel mapping and example uplink physical signals. FIG. 5B is a diagram of an example downlink channel mapping and a downlink physical signals. In an example, a physical layer may provide one or more information transfer services to a MAC and/or one or more higher layers. For example, the physical layer may provide the one or more information transfer services to the MAC via one or more transport channels. An information transfer service may indicate how and with what characteristics data are transferred over the radio interface.

In an example embodiment, a radio network may comprise one or more downlink and/or uplink transport channels. For example, a diagram in FIG. 5A shows example uplink transport channels comprising Uplink-Shared CHannel (UL-SCH) 501 and Random Access CHannel (RACH) 502. A diagram in FIG. 5B shows example downlink transport channels comprising Downlink-Shared CHannel (DL-SCH) 511, Paging CHannel (PCH) 512, and Broadcast CHannel (BCH) 513. A transport channel may be mapped to one or more corresponding physical channels. For example, UL-SCH 501 may be mapped to Physical Uplink Shared CHannel (PUSCH) 503. RACH 502 may be mapped to PRACH 505. DL-SCH 511 and PCH 512 may be mapped to Physical Downlink Shared CHannel (PDSCH) 514. BCH 513 may be mapped to Physical Broadcast CHannel (PBCH) 516.

There may be one or more physical channels without a corresponding transport channel. The one or more physical channels may be employed for Uplink Control Information (UCI) 509 and/or Downlink Control Information (DCI) 517. For example, Physical Uplink Control CHannel (PUCCH) 504 may carry UCI 509 from a UE to a base station. For example, Physical Downlink Control CHannel (PDCCH) 515 may carry DCI 517 from a base station to a UE. NR may support UCI 509 multiplexing in PUSCH 503 when UCI 509 and PUSCH 503 transmissions may coincide in a slot at least in part. The UCI 509 may comprise at least one of CSI, Acknowledgement (ACK)/Negative Acknowledgement (NACK), and/or scheduling request. The DCI 517 on PDCCH 515 may indicate at least one of following: one or more downlink assignments and/or one or more uplink scheduling grants

In uplink, a UE may transmit one or more Reference Signals (RSs) to a base station. For example, the one or more RSs may be at least one of Demodulation-RS (DM-RS) 506, Phase Tracking-RS (PT-RS) 507, and/or Sounding RS (SRS) 508. In downlink, a base station may transmit (e.g., unicast, multicast, and/or broadcast) one or more RSs to a UE. For example, the one or more RSs may be at least one of Primary Synchronization Signal (PSS)/Secondary Synchronization Signal (SSS) 521, CSI-RS 522, DM-RS 523, and/or PT-RS 524.

In an example, a UE may transmit one or more uplink DM-RSs 506 to a base station for channel estimation, for example, for coherent demodulation of one or more uplink physical channels (e.g., PUSCH 503 and/or PUCCH 504). For example, a UE may transmit a base station at least one uplink DM-RS 506 with PUSCH 503 and/or PUCCH 504, wherein the at least one uplink DM-RS 506 may be spanning a same frequency range as a corresponding physical channel. In an example, a base station may configure a UE with one or more uplink DM-RS configurations. At least one DM-RS configuration may support a front-loaded DM-RS pattern. A front-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). One or more additional uplink DM-RS may be configured to transmit at one or more symbols of a PUSCH and/or PUCCH. A base station may semi-statistically configure a UE with a maximum number of front-loaded DM-RS symbols for PUSCH and/or PUCCH. For example, a UE may schedule a single-symbol DM-RS and/or double symbol DM-RS based on a maximum number of front-loaded DM-RS symbols, wherein a base station may configure the UE with one or more additional uplink DM-RS for PUSCH and/or PUCCH. A new radio network may support, e.g., at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RS location, DM-RS pattern, and/or scrambling sequence may be same or different.

In an example, whether uplink PT-RS 507 is present or not may depend on a RRC configuration. For example, a presence of uplink PT-RS may be UE-specifically configured. For example, a presence and/or a pattern of uplink PT-RS 507 in a scheduled resource may be UE-specifically configured by a combination of RRC signaling and/or association with one or more parameters employed for other purposes (e.g., Modulation and Coding Scheme (MCS)) which may be indicated by DCI. When configured, a dynamic presence of uplink PT-RS 507 may be associated with one or more DCI parameters comprising at least MCS. A radio network may support plurality of uplink PT-RS densities defined in time/frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. A UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DM-RS ports in a scheduled resource. For example, uplink PT-RS 507 may be confined in the scheduled time/frequency duration for a UE.

In an example, a UE may transmit SRS 508 to a base station for channel state estimation to support uplink channel dependent scheduling and/or link adaptation. For example, SRS 508 transmitted by a UE may allow for a base station to estimate an uplink channel state at one or more different frequencies. A base station scheduler may employ an uplink channel state to assign one or more resource blocks of good quality for an uplink PUSCH transmission from a UE. A base station may semi-statistically configure a UE with one or more SRS resource sets. For an SRS resource set, a base station may configure a UE with one or more SRS resources. An SRS resource set applicability may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, a SRS resource in each of one or more SRS resource sets may be transmitted at a time instant. A UE may transmit one or more SRS resources in different SRS resource sets simultaneously. A new radio network may support aperiodic, periodic and/or semi-persistent SRS transmissions. A UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may comprise higher layer signaling (e.g., RRC) and/or one or more DCI formats (e.g., at least one DCI format may be employed for a UE to select at least one of one or more configured SRS resource sets. An SRS trigger type 0 may refer to an SRS triggered based on a higher layer signaling. An SRS trigger type 1 may refer to an SRS triggered based on one or more DCI formats. In an example, when PUSCH 503 and SRS 508 are transmitted in a same slot, a UE may be configured to transmit SRS 508 after a transmission of PUSCH 503 and corresponding uplink DM-RS 506.

In an example, a base station may semi-statistically configure a UE with one or more SRS configuration parameters indicating at least one of following: a SRS resource configuration identifier, a number of SRS ports, time domain behavior of SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS), slot (mini-slot, and/or subframe) level periodicity and/or offset for a periodic and/or aperiodic SRS resource, a number of OFDM symbols in a SRS resource, starting OFDM symbol of a SRS resource, a SRS bandwidth, a frequency hopping bandwidth, a cyclic shift, and/or a SRS sequence ID.

In an example, in a time domain, an SS/PBCH block may comprise one or more OFDM symbols (e.g., 4 OFDM symbols numbered in increasing order from 0 to 3) within the SS/PBCH block. An SS/PBCH block may comprise PSS/SSS 521 and PBCH 516. In an example, in the frequency domain, an SS/PBCH block may comprise one or more contiguous subcarriers (e.g., 240 contiguous subcarriers with the subcarriers numbered in increasing order from 0 to 239) within the SS/PBCH block. For example, a PSS/SSS 521 may occupy 1 OFDM symbol and 127 subcarriers. For example, PBCH 516 may span across 3 OFDM symbols and 240 subcarriers. A UE may assume that one or more SS/PBCH blocks transmitted with a same block index may be quasi co-located, e.g., with respect to Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters. A UE may not assume quasi co-location for other SS/PBCH block transmissions. A periodicity of an SS/PBCH block may be configured by a radio network (e.g., by an RRC signaling) and one or more time locations where the SS/PBCH block may be sent may be determined by sub-carrier spacing. In an example, a UE may assume a band-specific sub-carrier spacing for an SS/PBCH block unless a radio network has configured a UE to assume a different sub-carrier spacing.

In an example, downlink CSI-RS 522 may be employed for a UE to acquire channel state information. A radio network may support periodic, aperiodic, and/or semi-persistent transmission of downlink CSI-RS 522. For example, a base station may semi-statistically configure and/or reconfigure a UE with periodic transmission of downlink CSI-RS 522. A configured CSI-RS resources may be activated ad/or deactivated. For semi-persistent transmission, an activation and/or deactivation of CSI-RS resource may be triggered dynamically. In an example, CSI-RS configuration may comprise one or more parameters indicating at least a number of antenna ports. For example, a base station may configure a UE with 32 ports. A base station may semi-statistically configure a UE with one or more CSI-RS resource sets. One or more CSI-RS resources may be allocated from one or more CSI-RS resource sets to one or more UEs. For example, a base station may semi-statistically configure one or more parameters indicating CSI RS resource mapping, for example, time-domain location of one or more CSI-RS resources, a bandwidth of a CSI-RS resource, and/or a periodicity. In an example, a UE may be configured to employ a same OFDM symbols for downlink CSI-RS 522 and control resource set (coreset) when the downlink CSI-RS 522 and coreset are spatially quasi co-located and resource elements associated with the downlink CSI-RS 522 are the outside of PRB s configured for coreset. In an example, a UE may be configured to employ a same OFDM symbols for downlink CSI-RS 522 and SS/PBCH blocks when the downlink CSI-RS 522 and SS/PBCH blocks are spatially quasi co-located and resource elements associated with the downlink CSI-RS 522 are the outside of PRBs configured for SS/PBCH blocks.

In an example, a UE may transmit one or more downlink DM-RSs 523 to a base station for channel estimation, for example, for coherent demodulation of one or more downlink physical channels (e.g., PDSCH 514). For example, a radio network may support one or more variable and/or configurable DM-RS patterns for data demodulation. At least one downlink DM-RS configuration may support a front-loaded DM-RS pattern. A front-loaded DM-RS may be mapped over one or more OFDM symbols (e.g., 1 or 2 adjacent OFDM symbols). A base station may semi-statistically configure a UE with a maximum number of front-loaded DM-RS symbols for PDSCH 514. For example, a DM-RS configuration may support one or more DM-RS ports. For example, for single user-MIMO, a DM-RS configuration may support at least 8 orthogonal downlink DM-RS ports. For example, for multiuser-MIMO, a DM-RS configuration may support 12 orthogonal downlink DM-RS ports. A radio network may support, e.g., at least for CP-OFDM, a common DM-RS structure for DL and UL, wherein a DM-RS location, DM-RS pattern, and/or scrambling sequence may be same or different.

In an example, whether downlink PT-RS 524 is present or not may depend on a RRC configuration. For example, a presence of downlink PT-RS 524 may be UE-specifically configured. For example, a presence and/or a pattern of downlink PT-RS 524 in a scheduled resource may be UE-specifically configured by a combination of RRC signaling and/or association with one or more parameters employed for other purposes (e.g., MCS) which may be indicated by DCI. When configured, a dynamic presence of downlink PT-RS 524 may be associated with one or more DCI parameters comprising at least MCS. A radio network may support plurality of PT-RS densities defined in time/frequency domain. When present, a frequency domain density may be associated with at least one configuration of a scheduled bandwidth. A UE may assume a same precoding for a DMRS port and a PT-RS port. A number of PT-RS ports may be fewer than a number of DM-RS ports in a scheduled resource. For example, downlink PT-RS 524 may be confined in the scheduled time/frequency duration for a UE.

FIG. 6 is a diagram depicting an example transmission time and reception time for a carrier as per an aspect of an embodiment of the present disclosure. A multicarrier OFDM communication system may include one or more carriers, for example, ranging from 1 to 32 carriers, in case of carrier aggregation, or ranging from 1 to 64 carriers, in case of dual connectivity. Different radio frame structures may be supported (e.g., for FDD and for TDD duplex mechanisms). FIG. 6 shows an example frame timing. Downlink and uplink transmissions may be organized into radio frames 601. In this example, radio frame duration is 10 ms. In this example, a 10 ms radio frame 601 may be divided into ten equally sized subframes 602 with 1 ms duration. Subframe(s) may comprise one or more slots (e.g. slots 603 and 605) depending on subcarrier spacing and/or CP length. For example, a subframe with 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz and 480 kHz subcarrier spacing may comprise one, two, four, eight, sixteen and thirty-two slots, respectively. In FIG. 6, a subframe may be divided into two equally sized slots 603 with 0.5 ms duration. For example, 10 subframes may be available for downlink transmission and 10 subframes may be available for uplink transmissions in a 10 ms interval. Uplink and downlink transmissions may be separated in the frequency domain. Slot(s) may include a plurality of OFDM symbols 604. The number of OFDM symbols 604 in a slot 605 may depend on the cyclic prefix length. For example, a slot may be 14 OFDM symbols for the same subcarrier spacing of up to 480 kHz with normal CP. A slot may be 12 OFDM symbols for the same subcarrier spacing of 60 kHz with extended CP. A slot may contain downlink, uplink, or a downlink part and an uplink part and/or alike.

FIG. 7A is a diagram depicting example sets of OFDM subcarriers as per an aspect of an embodiment of the present disclosure. In the example, a gNB may communicate with a wireless device with a carrier with an example channel bandwidth 700. Arrow(s) in the diagram may depict a subcarrier in a multicarrier OFDM system. The OFDM system may use technology such as OFDM technology, SC-FDMA technology, and/or the like. In an example, an arrow 701 shows a subcarrier transmitting information symbols. In an example, a subcarrier spacing 702, between two contiguous subcarriers in a carrier, may be any one of 15 KHz, 30 KHz, 60 KHz, 120 KHz, 240 KHz etc. In an example, different subcarrier spacing may correspond to different transmission numerologies. In an example, a transmission numerology may comprise at least: a numerology index; a value of subcarrier spacing; a type of cyclic prefix (CP). In an example, a gNB may transmit to/receive from a UE on a number of subcarriers 703 in a carrier. In an example, a bandwidth occupied by a number of subcarriers 703 (transmission bandwidth) may be smaller than the channel bandwidth 700 of a carrier, due to guard band 704 and 705. In an example, a guard band 704 and 705 may be used to reduce interference to and from one or more neighbor carriers. A number of subcarriers (transmission bandwidth) in a carrier may depend on the channel bandwidth of the carrier and the subcarrier spacing. For example, a transmission bandwidth, for a carrier with 20 MHz channel bandwidth and 15 KHz subcarrier spacing, may be in number of 1024 subcarriers.

In an example, a gNB and a wireless device may communicate with multiple CCs when configured with CA. In an example, different component carriers may have different bandwidth and/or subcarrier spacing, if CA is supported. In an example, a gNB may transmit a first type of service to a UE on a first component carrier. The gNB may transmit a second type of service to the UE on a second component carrier. Different type of services may have different service requirement (e.g., data rate, latency, reliability), which may be suitable for transmission via different component carrier having different subcarrier spacing and/or bandwidth. FIG. 7B shows an example embodiment. A first component carrier may comprise a first number of subcarriers 706 with a first subcarrier spacing 709. A second component carrier may comprise a second number of subcarriers 707 with a second subcarrier spacing 710. A third component carrier may comprise a third number of subcarriers 708 with a third subcarrier spacing 711. Carriers in a multicarrier OFDM communication system may be contiguous carriers, non-contiguous carriers, or a combination of both contiguous and non-contiguous carriers.

FIG. 8 is a diagram depicting OFDM radio resources as per an aspect of an embodiment of the present disclosure. In an example, a carrier may have a transmission bandwidth 801. In an example, a resource grid may be in a structure of frequency domain 802 and time domain 803. In an example, a resource grid may comprise a first number of OFDM symbols in a subframe and a second number of resource blocks, starting from a common resource block indicated by higher-layer signaling (e.g. RRC signaling), for a transmission numerology and a carrier. In an example, in a resource grid, a resource unit identified by a subcarrier index and a symbol index may be a resource element 805. In an example, a subframe may comprise a first number of OFDM symbols 807 depending on a numerology associated with a carrier. For example, when a subcarrier spacing of a numerology of a carrier is 15 KHz, a subframe may have 14 OFDM symbols for a carrier. When a subcarrier spacing of a numerology is 30 KHz, a subframe may have 28 OFDM symbols. When a subcarrier spacing of a numerology is 60 Khz, a subframe may have 56 OFDM symbols, etc. In an example, a second number of resource blocks comprised in a resource grid of a carrier may depend on a bandwidth and a numerology of the carrier.

As shown in FIG. 8, a resource block 806 may comprise 12 subcarriers. In an example, multiple resource blocks may be grouped into a Resource Block Group (RBG) 804. In an example, a size of a RBG may depend on at least one of: a RRC message indicating a RBG size configuration; a size of a carrier bandwidth; or a size of a bandwidth part of a carrier. In an example, a carrier may comprise multiple bandwidth parts. A first bandwidth part of a carrier may have different frequency location and/or bandwidth from a second bandwidth part of the carrier.

In an example, a gNB may transmit a downlink control information comprising a downlink or uplink resource block assignment to a wireless device. A base station may transmit to or receive from, a wireless device, data packets (e.g. transport blocks) scheduled and transmitted via one or more resource blocks and one or more slots according to parameters in a downlink control information and/or RRC message(s). In an example, a starting symbol relative to a first slot of the one or more slots may be indicated to the wireless device. In an example, a gNB may transmit to or receive from, a wireless device, data packets scheduled on one or more RBGs and one or more slots.

In an example, a gNB may transmit a downlink control information comprising a downlink assignment to a wireless device via one or more PDCCHs. The downlink assignment may comprise parameters indicating at least modulation and coding format; resource allocation; and/or HARQ information related to DL-SCH. In an example, a resource allocation may comprise parameters of resource block allocation; and/or slot allocation. In an example, a gNB may dynamically allocate resources to a wireless device via a Cell-Radio Network Temporary Identifier (C-RNTI) on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs in order to find possible allocation when its downlink reception is enabled. The wireless device may receive one or more downlink data package on one or more PDSCH scheduled by the one or more PDCCHs, when successfully detecting the one or more PDCCHs.

In an example, a gNB may allocate Configured Scheduling (CS) resources for down link transmission to a wireless device. The gNB may transmit one or more RRC messages indicating a periodicity of the CS grant. The gNB may transmit a DCI via a PDCCH addressed to a Configured Scheduling-RNTI (CS-RNTI) activating the CS resources. The DCI may comprise parameters indicating that the downlink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC messages, until deactivated.

In an example, a gNB may transmit a downlink control information comprising an uplink grant to a wireless device via one or more PDCCHs. The uplink grant may comprise parameters indicating at least modulation and coding format; resource allocation; and/or HARQ information related to UL-SCH. In an example, a resource allocation may comprise parameters of resource block allocation; and/or slot allocation. In an example, a gNB may dynamically allocate resources to a wireless device via a C-RNTI on one or more PDCCHs. The wireless device may monitor the one or more PDCCHs in order to find possible resource allocation. The wireless device may transmit one or more uplink data package via one or more PUSCH scheduled by the one or more PDCCHs, when successfully detecting the one or more PDCCHs.

In an example, a gNB may allocate CS resources for uplink data transmission to a wireless device. The gNB may transmit one or more RRC messages indicating a periodicity of the CS grant. The gNB may transmit a DCI via a PDCCH addressed to a CS-RNTI activating the CS resources. The DCI may comprise parameters indicating that the uplink grant is a CS grant. The CS grant may be implicitly reused according to the periodicity defined by the one or more RRC message, until deactivated.

In an example, a base station may transmit DCI/control signaling via PDCCH. The DCI may take a format in a plurality of formats. A DCI may comprise downlink and/or uplink scheduling information (e.g., resource allocation information, HARQ related parameters, MCS), request for CSI (e.g., aperiodic CQI reports), request for SRS, uplink power control commands for one or more cells, one or more timing information (e.g., TB transmission/reception timing, HARQ feedback timing, etc.), etc. In an example, a DCI may indicate an uplink grant comprising transmission parameters for one or more transport blocks. In an example, a DCI may indicate downlink assignment indicating parameters for receiving one or more transport blocks. In an example, a DCI may be used by base station to initiate a contention-free random access at the wireless device. In an example, the base station may transmit a DCI comprising slot format indicator (SFI) notifying a slot format. In an example, the base station may transmit a DCI comprising pre-emption indication notifying the PRB(s) and/or OFDM symbol(s) where a UE may assume no transmission is intended for the UE. In an example, the base station may transmit a DCI for group power control of PUCCH or PUSCH or SRS. In an example, a DCI may correspond to an RNTI. In an example, the wireless device may obtain an RNTI in response to completing the initial access (e.g., C-RNTI). In an example, the base station may configure an RNTI for the wireless (e.g., CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI). In an example, the wireless device may compute an RNTI (e.g., the wireless device may compute RA-RNTI based on resources used for transmission of a preamble). In an example, an RNTI may have a pre-configured value (e.g., P-RNTI or SI-RNTI). In an example, a wireless device may monitor a group common search space which may be used by base station for transmitting DCIs that are intended for a group of UEs. In an example, a group common DCI may correspond to an RNTI which is commonly configured for a group of UEs. In an example, a wireless device may monitor a UE-specific search space. In an example, a UE specific DCI may correspond to an RNTI configured for the wireless device.

A NR system may support a single beam operation and/or a multi-beam operation. In a multi-beam operation, a base station may perform a downlink beam sweeping to provide coverage for common control channels and/or downlink SS blocks, which may comprise at least a PSS, a SSS, and/or PBCH. A wireless device may measure quality of a beam pair link using one or more RSs. One or more SS blocks, or one or more CSI-RS resources, associated with a CSI-RS resource index (CRI), or one or more DM-RSs of PBCH, may be used as RS for measuring quality of a beam pair link. Quality of a beam pair link may be defined as a reference signal received power (RSRP) value, or a reference signal received quality (RSRQ) value, and/or a CSI value measured on RS resources. The base station may indicate whether an RS resource, used for measuring a beam pair link quality, is quasi-co-located (QCLed) with DM-RSs of a control channel. A RS resource and DM-RSs of a control channel may be called QCLed when a channel characteristics from a transmission on an RS to a wireless device, and that from a transmission on a control channel to a wireless device, are similar or same under a configured criterion. In a multi-beam operation, a wireless device may perform an uplink beam sweeping to access a cell.

In an example, a wireless device may be configured to monitor PDCCH on one or more beam pair links simultaneously depending on a capability of a wireless device. This may increase robustness against beam pair link blocking. A base station may transmit one or more messages to configure a wireless device to monitor PDCCH on one or more beam pair links in different PDCCH OFDM symbols. For example, a base station may transmit higher layer signaling (e.g. RRC signaling) or MAC CE comprising parameters related to the Rx beam setting of a wireless device for monitoring PDCCH on one or more beam pair links. A base station may transmit indication of spatial QCL assumption between an DL RS antenna port(s) (for example, cell-specific CSI-RS, or wireless device-specific CSI-RS, or SS block, or PBCH with or without DM-RSs of PBCH), and DL RS antenna port(s) for demodulation of DL control channel. Signaling for beam indication for a PDCCH may be MAC CE signaling, or RRC signaling, or DCI signaling, or specification-transparent and/or implicit method, and combination of these signaling methods.

For reception of unicast DL data channel, a base station may indicate spatial QCL parameters between DL RS antenna port(s) and DM-RS antenna port(s) of DL data channel. The base station may transmit DCI (e.g. downlink grants) comprising information indicating the RS antenna port(s). The information may indicate RS antenna port(s) which may be QCLed with the DM-RS antenna port(s). Different set of DM-RS antenna port(s) for a DL data channel may be indicated as QCL with different set of the RS antenna port(s).

FIG. 9A is an example of beam sweeping in a DL channel. In an RRC_INACTIVE state or RRC_IDLE state, a wireless device may assume that SS blocks form an SS burst 940, and an SS burst set 950. The SS burst set 950 may have a given periodicity. For example, in a multi-beam operation, a base station 120 may transmit SS blocks in multiple beams, together forming a SS burst 940. One or more SS blocks may be transmitted on one beam. If multiple SS bursts 940 are transmitted with multiple beams, SS bursts together may form SS burst set 950.

A wireless device may further use CSI-RS in the multi-beam operation for estimating a beam quality of a links between a wireless device and a base station. A beam may be associated with a CSI-RS. For example, a wireless device may, based on a RSRP measurement on CSI-RS, report a beam index, as indicated in a CRI for downlink beam selection, and associated with a RSRP value of a beam. A CSI-RS may be transmitted on a CSI-RS resource including at least one of one or more antenna ports, one or more time or frequency radio resources. A CSI-RS resource may be configured in a cell-specific way by common RRC signaling, or in a wireless device-specific way by dedicated RRC signaling, and/or L1/L2 signaling. Multiple wireless devices covered by a cell may measure a cell-specific CSI-RS resource. A dedicated subset of wireless devices covered by a cell may measure a wireless device-specific CSI-RS resource.

A CSI-RS resource may be transmitted periodically, or using aperiodic transmission, or using a multi-shot or semi-persistent transmission. For example, in a periodic transmission in FIG. 9A, a base station 120 may transmit configured CSI-RS resources 940 periodically using a configured periodicity in a time domain. In an aperiodic transmission, a configured CSI-RS resource may be transmitted in a dedicated time slot. In a multi-shot or semi-persistent transmission, a configured CSI-RS resource may be transmitted within a configured period. Beams used for CSI-RS transmission may have different beam width than beams used for SS-blocks transmission.

FIG. 9B is an example of a beam management procedure in an example new radio network. A base station 120 and/or a wireless device 110 may perform a downlink L1/L2 beam management procedure. One or more of the following downlink L1/L2 beam management procedures may be performed within one or more wireless devices 110 and one or more base stations 120. In an example, a P-1 procedure 910 may be used to enable the wireless device 110 to measure one or more Transmission (Tx) beams associated with the base station 120 to support a selection of a first set of Tx beams associated with the base station 120 and a first set of Rx beam(s) associated with a wireless device 110. For beamforming at a base station 120, a base station 120 may sweep a set of different TX beams. For beamforming at a wireless device 110, a wireless device 110 may sweep a set of different Rx beams. In an example, a P-2 procedure 920 may be used to enable a wireless device 110 to measure one or more Tx beams associated with a base station 120 to possibly change a first set of Tx beams associated with a base station 120. A P-2 procedure 920 may be performed on a possibly smaller set of beams for beam refinement than in the P-1 procedure 910. A P-2 procedure 920 may be a special case of a P-1 procedure 910. In an example, a P-3 procedure 930 may be used to enable a wireless device 110 to measure at least one Tx beam associated with a base station 120 to change a first set of Rx beams associated with a wireless device 110.

A wireless device 110 may transmit one or more beam management reports to a base station 120. In one or more beam management reports, a wireless device 110 may indicate some beam pair quality parameters, comprising at least, one or more beam identifications; RSRP; Precoding Matrix Indicator (PMI)/Channel Quality Indicator (CQI)/Rank Indicator (RI) of a subset of configured beams. Based on one or more beam management reports, a base station 120 may transmit to a wireless device 110 a signal indicating that one or more beam pair links are one or more serving beams. A base station 120 may transmit PDCCH and PDSCH for a wireless device 110 using one or more serving beams.

In an example embodiment, new radio network may support a Bandwidth Adaptation (BA). In an example, receive and/or transmit bandwidths configured by an UE employing a BA may not be large. For example, a receive and/or transmit bandwidths may not be as large as a bandwidth of a cell. Receive and/or transmit bandwidths may be adjustable. For example, a UE may change receive and/or transmit bandwidths, e.g., to shrink during period of low activity to save power. For example, a UE may change a location of receive and/or transmit bandwidths in a frequency domain, e.g. to increase scheduling flexibility. For example, a UE may change a subcarrier spacing, e.g. to allow different services.

In an example embodiment, a subset of a total cell bandwidth of a cell may be referred to as a Bandwidth Part (BWP). A base station may configure a UE with one or more BWPs to achieve a BA. For example, a base station may indicate, to a UE, which of the one or more (configured) BWPs is an active BWP.

FIG. 10 is an example diagram of 3 BWPs configured: BWP1 (1010 and 1050) with a width of 40 MHz and subcarrier spacing of 15 kHz; BWP2 (1020 and 1040) with a width of 10 MHz and subcarrier spacing of 15 kHz; BWP3 1030 with a width of 20 MHz and subcarrier spacing of 60 kHz.

In an example, a UE, configured for operation in one or more BWPs of a cell, may be configured by one or more higher layers (e.g. RRC layer) for a cell a set of one or more BWPs (e.g., at most four BWPs) for receptions by the UE (DL BWP set) in a DL bandwidth by at least one parameter DL-BWP and a set of one or more BWPs (e.g., at most four BWPs) for transmissions by a UE (UL BWP set) in an UL bandwidth by at least one parameter UL-BWP for a cell.

To enable BA on the PCell, a base station may configure a UE with one or more UL and DL BWP pairs. To enable BA on SCells (e.g., in case of CA), a base station may configure a UE at least with one or more DL BWPs (e.g., there may be none in an UL).

In an example, an initial active DL BWP may be defined by at least one of a location and number of contiguous PRBs, a subcarrier spacing, or a cyclic prefix, for a control resource set for at least one common search space. For operation on the PCell, one or more higher layer parameters may indicate at least one initial UL BWP for a random access procedure. If a UE is configured with a secondary carrier on a primary cell, the UE may be configured with an initial BWP for random access procedure on a secondary carrier.

In an example, for unpaired spectrum operation, a UE may expect that a center frequency for a DL BWP may be same as a center frequency for a UL BWP.

For example, for a DL BWP or an UL BWP in a set of one or more DL BWPs or one or more UL BWPs, respectively, a base station may semi-statistically configure a UE for a cell with one or more parameters indicating at least one of following: a subcarrier spacing; a cyclic prefix; a number of contiguous PRBs; an index in the set of one or more DL BWPs and/or one or more UL BWPs; a link between a DL BWP and an UL BWP from a set of configured DL BWPs and UL BWPs; a DCI detection to a PDSCH reception timing; a PDSCH reception to a HARQ-ACK transmission timing value; a DCI detection to a PUSCH transmission timing value; an offset of a first PRB of a DL bandwidth or an UL bandwidth, respectively, relative to a first PRB of a bandwidth.

In an example, for a DL BWP in a set of one or more DL BWPs on a PCell, a base station may configure a UE with one or more control resource sets for at least one type of common search space and/or one UE-specific search space. For example, a base station may not configure a UE without a common search space on a PCell, or on a PSCell, in an active DL BWP.

For an UL BWP in a set of one or more UL BWPs, a base station may configure a UE with one or more resource sets for one or more PUCCH transmissions.

In an example, if a DCI comprises a BWP indicator field, a BWP indicator field value may indicate an active DL BWP, from a configured DL BWP set, for one or more DL receptions. If a DCI comprises a BWP indicator field, a BWP indicator field value may indicate an active UL BWP, from a configured UL BWP set, for one or more UL transmissions.

In an example, for a PCell, a base station may semi-statistically configure a UE with a default DL BWP among configured DL BWPs. If a UE is not provided a default DL BWP, a default BWP may be an initial active DL BWP.

In an example, a base station may configure a UE with a timer value for a PCell. For example, a UE may start a timer, referred to as BWP inactivity timer, when a UE detects a DCI indicating an active DL BWP, other than a default DL BWP, for a paired spectrum operation or when a UE detects a DCI indicating an active DL BWP or UL BWP, other than a default DL BWP or UL BWP, for an unpaired spectrum operation. The UE may increment the timer by an interval of a first value (e.g., the first value may be 1 millisecond or 0.5 milliseconds) if the UE does not detect a DCI during the interval for a paired spectrum operation or for an unpaired spectrum operation. In an example, the timer may expire when the timer is equal to the timer value. A UE may switch to the default DL BWP from an active DL BWP when the timer expires.

In an example, a base station may semi-statistically configure a UE with one or more BWPs. A UE may switch an active BWP from a first BWP to a second BWP in response to receiving a DCI indicating the second BWP as an active BWP and/or in response to an expiry of BWP inactivity timer (for example, the second BWP may be a default BWP). For example, FIG. 10 is an example diagram of 3 BWPs configured, BWP1 (1010 and 1050), BWP2 (1020 and 1040), and BWP3 (1030). BWP2 (1020 and 1040) may be a default BWP. BWP1 (1010) may be an initial active BWP. In an example, a UE may switch an active BWP from BWP1 1010 to BWP2 1020 in response to an expiry of BWP inactivity timer. For example, a UE may switch an active BWP from BWP2 1020 to BWP3 1030 in response to receiving a DCI indicating BWP3 1030 as an active BWP. Switching an active BWP from BWP3 1030 to BWP2 1040 and/or from BWP2 1040 to BWP1 1050 may be in response to receiving a DCI indicating an active BWP and/or in response to an expiry of BWP inactivity timer.

In an example, if a UE is configured for a secondary cell with a default DL BWP among configured DL BWPs and a timer value, UE procedures on a secondary cell may be same as on a primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell.

In an example, if a base station configures a UE with a first active DL BWP and a first active UL BWP on a secondary cell or carrier, a UE may employ an indicated DL BWP and an indicated UL BWP on a secondary cell as a respective first active DL BWP and first active UL BWP on a secondary cell or carrier.

FIG. 11A and FIG. 11B show packet flows employing a multi connectivity (e.g. dual connectivity, multi connectivity, tight interworking, and/or the like). FIG. 11A is an example diagram of a protocol structure of a wireless device 110 (e.g. UE) with CA and/or multi connectivity as per an aspect of an embodiment. FIG. 11B is an example diagram of a protocol structure of multiple base stations with CA and/or multi connectivity as per an aspect of an embodiment. The multiple base stations may comprise a master node, MN 1130 (e.g. a master node, a master base station, a master gNB, a master eNB, and/or the like) and a secondary node, SN 1150 (e.g. a secondary node, a secondary base station, a secondary gNB, a secondary eNB, and/or the like). A master node 1130 and a secondary node 1150 may co-work to communicate with a wireless device 110.

When multi connectivity is configured for a wireless device 110, the wireless device 110, which may support multiple reception/transmission functions in an RRC connected state, may be configured to utilize radio resources provided by multiple schedulers of a multiple base stations. Multiple base stations may be inter-connected via a non-ideal or ideal backhaul (e.g. Xn interface, X2 interface, and/or the like). A base station involved in multi connectivity for a certain wireless device may perform at least one of two different roles: a base station may either act as a master base station or as a secondary base station. In multi connectivity, a wireless device may be connected to one master base station and one or more secondary base stations. In an example, a master base station (e.g. the MN 1130) may provide a master cell group (MCG) comprising a primary cell and/or one or more secondary cells for a wireless device (e.g. the wireless device 110). A secondary base station (e.g. the SN 1150) may provide a secondary cell group (SCG) comprising a primary secondary cell (PSCell) and/or one or more secondary cells for a wireless device (e.g. the wireless device 110).

In multi connectivity, a radio protocol architecture that a bearer employs may depend on how a bearer is setup. In an example, three different type of bearer setup options may be supported: an MCG bearer, an SCG bearer, and/or a split bearer. A wireless device may receive/transmit packets of an MCG bearer via one or more cells of the MCG, and/or may receive/transmits packets of an SCG bearer via one or more cells of an SCG. Multi-connectivity may also be described as having at least one bearer configured to use radio resources provided by the secondary base station. Multi-connectivity may or may not be configured/implemented in some of the example embodiments.

In an example, a wireless device (e.g. Wireless Device 110) may transmit and/or receive: packets of an MCG bearer via an SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1111), an RLC layer (e.g. MN RLC 1114), and a MAC layer (e.g. MN MAC 1118); packets of a split bearer via an SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1112), one of a master or secondary RLC layer (e.g. MN RLC 1115, SN RLC 1116), and one of a master or secondary MAC layer (e.g. MN MAC 1118, SN MAC 1119); and/or packets of an SCG bearer via an SDAP layer (e.g. SDAP 1110), a PDCP layer (e.g. NR PDCP 1113), an RLC layer (e.g. SN RLC 1117), and a MAC layer (e.g. MN MAC 1119).

In an example, a master base station (e.g. MN 1130) and/or a secondary base station (e.g. SN 1150) may transmit/receive: packets of an MCG bearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), a master or secondary node PDCP layer (e.g. NR PDCP 1121, NR PDCP 1142), a master node RLC layer (e.g. MN RLC 1124, MN RLC 1125), and a master node MAC layer (e.g. MN MAC 1128); packets of an SCG bearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), a master or secondary node PDCP layer (e.g. NR PDCP 1122, NR PDCP 1143), a secondary node RLC layer (e.g. SN RLC 1146, SN RLC 1147), and a secondary node MAC layer (e.g. SN MAC 1148); packets of a split bearer via a master or secondary node SDAP layer (e.g. SDAP 1120, SDAP 1140), a master or secondary node PDCP layer (e.g. NR PDCP 1123, NR PDCP 1141), a master or secondary node RLC layer (e.g. MN RLC 1126, SN RLC 1144, SN RLC 1145, MN RLC 1127), and a master or secondary node MAC layer (e.g. MN MAC 1128, SN MAC 1148).

In multi connectivity, a wireless device may configure multiple MAC entities: one MAC entity (e.g. MN MAC 1118) for a master base station, and other MAC entities (e.g. SN MAC 1119) for a secondary base station. In multi-connectivity, a configured set of serving cells for a wireless device may comprise two subsets: an MCG comprising serving cells of a master base station, and SCGs comprising serving cells of a secondary base station. For an SCG, one or more of following configurations may be applied: at least one cell of an SCG has a configured UL CC and at least one cell of a SCG, named as primary secondary cell (PSCell, PCell of SCG, or sometimes called PCell), is configured with PUCCH resources; when an SCG is configured, there may be at least one SCG bearer or one Split bearer; upon detection of a physical layer problem or a random access problem on a PSCell, or a number of NR RLC retransmissions has been reached associated with the SCG, or upon detection of an access problem on a PSCell during a SCG addition or a SCG change: an RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of an SCG may be stopped, a master base station may be informed by a wireless device of a SCG failure type, for split bearer, a DL data transfer over a master base station may be maintained; an NR RLC acknowledged mode (AM) bearer may be configured for a split bearer; PCell and/or PSCell may not be de-activated; PSCell may be changed with a SCG change procedure (e.g. with security key change and a RACH procedure); and/or a bearer type change between a split bearer and a SCG bearer or simultaneous configuration of a SCG and a split bearer may or may not supported.

With respect to interaction between a master base station and a secondary base stations for multi-connectivity, one or more of the following may be applied: a master base station and/or a secondary base station may maintain Radio Resource Management (RRM) measurement configurations of a wireless device; a master base station may (e.g. based on received measurement reports, traffic conditions, and/or bearer types) may decide to request a secondary base station to provide additional resources (e.g. serving cells) for a wireless device; upon receiving a request from a master base station, a secondary base station may create/modify a container that may result in configuration of additional serving cells for a wireless device (or decide that the secondary base station has no resource available to do so); for a UE capability coordination, a master base station may provide (a part of) an AS configuration and UE capabilities to a secondary base station; a master base station and a secondary base station may exchange information about a UE configuration by employing of RRC containers (inter-node messages) carried via Xn messages; a secondary base station may initiate a reconfiguration of the secondary base station existing serving cells (e.g. PUCCH towards the secondary base station); a secondary base station may decide which cell is a PSCell within a SCG; a master base station may or may not change content of RRC configurations provided by a secondary base station; in case of a SCG addition and/or a SCG SCell addition, a master base station may provide recent (or the latest) measurement results for SCG cell(s); a master base station and secondary base stations may receive information of SFN and/or subframe offset of each other from OAM and/or via an Xn interface, (e.g. for a purpose of DRX alignment and/or identification of a measurement gap). In an example, when adding a new SCG SCell, dedicated RRC signaling may be used for sending required system information of a cell as for CA, except for a SFN acquired from a MIB of a PSCell of a SCG.

FIG. 12 is an example diagram of a random access procedure. One or more events may trigger a random access procedure. For example, one or more events may be at least one of following: initial access from RRC_IDLE, RRC connection re-establishment procedure, handover, DL or UL data arrival during RRC_CONNECTED when UL synchronization status is non-synchronized, transition from RRC_Inactive, and/or request for other system information. For example, a PDCCH order, a MAC entity, and/or a beam failure indication may initiate a random access procedure.

In an example embodiment, a random access procedure may be at least one of a contention based random access procedure and a contention free random access procedure. For example, a contention based random access procedure may comprise, one or more Msg 1 1220 transmissions, one or more Msg2 1230 transmissions, one or more Msg3 1240 transmissions, and contention resolution 1250. For example, a contention free random access procedure may comprise one or more Msg 1 1220 transmissions and one or more Msg2 1230 transmissions.

In an example, a base station may transmit (e.g., unicast, multicast, or broadcast), to a UE, a RACH configuration 1210 via one or more beams. The RACH configuration 1210 may comprise one or more parameters indicating at least one of following: available set of PRACH resources for a transmission of a random access preamble, initial preamble power (e.g., random access preamble initial received target power), an RSRP threshold for a selection of a SS block and corresponding PRACH resource, a power-ramping factor (e.g., random access preamble power ramping step), random access preamble index, a maximum number of preamble transmission, preamble group A and group B, a threshold (e.g., message size) to determine the groups of random access preambles, a set of one or more random access preambles for system information request and corresponding PRACH resource(s), if any, a set of one or more random access preambles for beam failure recovery request and corresponding PRACH resource(s), if any, a time window to monitor RA response(s), a time window to monitor response(s) on beam failure recovery request, and/or a contention resolution timer.

In an example, the Msg1 1220 may be one or more transmissions of a random access preamble. For a contention based random access procedure, a UE may select a SS block with a RSRP above the RSRP threshold. If random access preambles group B exists, a UE may select one or more random access preambles from a group A or a group B depending on a potential Msg3 1240 size. If a random access preambles group B does not exist, a UE may select the one or more random access preambles from a group A. A UE may select a random access preamble index randomly (e.g. with equal probability or a normal distribution) from one or more random access preambles associated with a selected group. If a base station semi-statistically configures a UE with an association between random access preambles and SS blocks, the UE may select a random access preamble index randomly with equal probability from one or more random access preambles associated with a selected SS block and a selected group.

For example, a UE may initiate a contention free random access procedure based on a beam failure indication from a lower layer. For example, a base station may semi-statistically configure a UE with one or more contention free PRACH resources for beam failure recovery request associated with at least one of SS blocks and/or CSI-RSs. If at least one of SS blocks with a RSRP above a first RSRP threshold amongst associated SS blocks or at least one of CSI-RSs with a RSRP above a second RSRP threshold amongst associated CSI-RSs is available, a UE may select a random access preamble index corresponding to a selected SS block or CSI-RS from a set of one or more random access preambles for beam failure recovery request.

For example, a UE may receive, from a base station, a random access preamble index via PDCCH or RRC for a contention free random access procedure. If a base station does not configure a UE with at least one contention free PRACH resource associated with SS blocks or CSI-RS, the UE may select a random access preamble index. If a base station configures a UE with one or more contention free PRACH resources associated with SS blocks and at least one SS block with a RSRP above a first RSRP threshold amongst associated SS blocks is available, the UE may select the at least one SS block and select a random access preamble corresponding to the at least one SS block. If a base station configures a UE with one or more contention free PRACH resources associated with CSI-RSs and at least one CSI-RS with a RSRP above a second RSPR threshold amongst the associated CSI-RSs is available, the UE may select the at least one CSI-RS and select a random access preamble corresponding to the at least one CSI-RS.

A UE may perform one or more Msg1 1220 transmissions by transmitting the selected random access preamble. For example, if a UE selects an SS block and is configured with an association between one or more PRACH occasions and one or more SS blocks, the UE may determine an PRACH occasion from one or more PRACH occasions corresponding to a selected SS block. For example, if a UE selects a CSI-RS and is configured with an association between one or more PRACH occasions and one or more CSI-RSs, the UE may determine a PRACH occasion from one or more PRACH occasions corresponding to a selected CSI-RS. A UE may transmit, to a base station, a selected random access preamble via a selected PRACH occasions. A UE may determine a transmit power for a transmission of a selected random access preamble at least based on an initial preamble power and a power-ramping factor. A UE may determine a RA-RNTI associated with a selected PRACH occasions in which a selected random access preamble is transmitted. For example, a UE may not determine a RA-RNTI for a beam failure recovery request. A UE may determine an RA-RNTI at least based on an index of a first OFDM symbol and an index of a first slot of a selected PRACH occasions, and/or an uplink carrier index for a transmission of Msg1 1220.

In an example, a UE may receive, from a base station, a random access response, Msg 2 1230. A UE may start a time window (e.g., ra-ResponseWindow) to monitor a random access response. For beam failure recovery request, a base station may configure a UE with a different time window (e.g., bfr-ResponseWindow) to monitor response on beam failure recovery request. For example, a UE may start a time window (e.g., ra-ResponseWindow or bfr-ResponseWindow) at a start of a first PDCCH occasion after a fixed duration of one or more symbols from an end of a preamble transmission. If a UE transmits multiple preambles, the UE may start a time window at a start of a first PDCCH occasion after a fixed duration of one or more symbols from an end of a first preamble transmission. A UE may monitor a PDCCH of a cell for at least one random access response identified by a RA-RNTI or for at least one response to beam failure recovery request identified by a C-RNTI while a timer for a time window is running.

In an example, a UE may consider a reception of random access response successful if at least one random access response comprises a random access preamble identifier corresponding to a random access preamble transmitted by the UE. A UE may consider the contention free random access procedure successfully completed if a reception of random access response is successful. If a contention free random access procedure is triggered for a beam failure recovery request, a UE may consider a contention free random access procedure successfully complete if a PDCCH transmission is addressed to a C-RNTI. In an example, if at least one random access response comprises a random access preamble identifier, a UE may consider the random access procedure successfully completed and may indicate a reception of an acknowledgement for a system information request to upper layers. If a UE has signaled multiple preamble transmissions, the UE may stop transmitting remaining preambles (if any) in response to a successful reception of a corresponding random access response.

In an example, a UE may perform one or more Msg 3 1240 transmissions in response to a successful reception of random access response (e.g., for a contention based random access procedure). A UE may adjust an uplink transmission timing based on a timing advanced command indicated by a random access response and may transmit one or more transport blocks based on an uplink grant indicated by a random access response. Subcarrier spacing for PUSCH transmission for Msg3 1240 may be provided by at least one higher layer (e.g. RRC) parameter. A UE may transmit a random access preamble via PRACH and Msg3 1240 via PUSCH on a same cell. A base station may indicate an UL BWP for a PUSCH transmission of Msg3 1240 via system information block. A UE may employ HARQ for a retransmission of Msg 3 1240.

In an example, multiple UEs may perform Msg 1 1220 by transmitting a same preamble to a base station and receive, from the base station, a same random access response comprising an identity (e.g., TC-RNTI). Contention resolution 1250 may ensure that a UE does not incorrectly use an identity of another UE. For example, contention resolution 1250 may be based on C-RNTI on PDCCH or a UE contention resolution identity on DL-SCH. For example, if a base station assigns a C-RNTI to a UE, the UE may perform contention resolution 1250 based on a reception of a PDCCH transmission that is addressed to the C-RNTI. In response to detection of a C-RNTI on a PDCCH, a UE may consider contention resolution 1250 successful and may consider a random access procedure successfully completed. If a UE has no valid C-RNTI, a contention resolution may be addressed by employing a TC-RNTI. For example, if a MAC PDU is successfully decoded and a MAC PDU comprises a UE contention resolution identity MAC CE that matches the CCCH SDU transmitted in Msg3 1250, a UE may consider the contention resolution 1250 successful and may consider the random access procedure successfully completed.

FIG. 13 is an example structure for MAC entities as per an aspect of an embodiment. In an example, a wireless device may be configured to operate in a multi-connectivity mode. A wireless device in RRC_CONNECTED with multiple RX/TX may be configured to utilize radio resources provided by multiple schedulers located in a plurality of base stations. The plurality of base stations may be connected via a non-ideal or ideal backhaul over the Xn interface. In an example, a base station in a plurality of base stations may act as a master base station or as a secondary base station. A wireless device may be connected to one master base station and one or more secondary base stations. A wireless device may be configured with multiple MAC entities, e.g. one MAC entity for master base station, and one or more other MAC entities for secondary base station(s). In an example, a configured set of serving cells for a wireless device may comprise two subsets: an MCG comprising serving cells of a master base station, and one or more SCGs comprising serving cells of a secondary base station(s). FIG. 13 illustrates an example structure for MAC entities when MCG and SCG are configured for a wireless device.

In an example, at least one cell in a SCG may have a configured UL CC, wherein a cell of at least one cell may be called PSCell or PCell of SCG, or sometimes may be simply called PCell. A PSCell may be configured with PUCCH resources. In an example, when a SCG is configured, there may be at least one SCG bearer or one split bearer. In an example, upon detection of a physical layer problem or a random access problem on a PSCell, or upon reaching a number of RLC retransmissions associated with the SCG, or upon detection of an access problem on a PSCell during a SCG addition or a SCG change: an RRC connection re-establishment procedure may not be triggered, UL transmissions towards cells of an SCG may be stopped, a master base station may be informed by a UE of a SCG failure type and DL data transfer over a master base station may be maintained.

In an example, a MAC sublayer may provide services such as data transfer and radio resource allocation to upper layers (e.g. 1310 or 1320). A MAC sublayer may comprise a plurality of MAC entities (e.g. 1350 and 1360). A MAC sublayer may provide data transfer services on logical channels. To accommodate different kinds of data transfer services, multiple types of logical channels may be defined. A logical channel may support transfer of a particular type of information. A logical channel type may be defined by what type of information (e.g., control or data) is transferred. For example, BCCH, PCCH, CCCH and DCCH may be control channels and DTCH may be a traffic channel. In an example, a first MAC entity (e.g. 1310) may provide services on PCCH, BCCH, CCCH, DCCH, DTCH and MAC control elements. In an example, a second MAC entity (e.g. 1320) may provide services on BCCH, DCCH, DTCH and MAC control elements.

A MAC sublayer may expect from a physical layer (e.g. 1330 or 1340) services such as data transfer services, signaling of HARQ feedback, signaling of scheduling request or measurements (e.g. CQI). In an example, in dual connectivity, two MAC entities may be configured for a wireless device: one for MCG and one for SCG. A MAC entity of wireless device may handle a plurality of transport channels. In an example, a first MAC entity may handle first transport channels comprising a PCCH of MCG, a first BCH of MCG, one or more first DL-SCHs of MCG, one or more first UL-SCHs of MCG and one or more first RACHs of MCG. In an example, a second MAC entity may handle second transport channels comprising a second BCH of SCG, one or more second DL-SCHs of SCG, one or more second UL-SCHs of SCG and one or more second RACHs of SCG.

In an example, if a MAC entity is configured with one or more SCells, there may be multiple DL-SCHs and there may be multiple UL-SCHs as well as multiple RACHs per MAC entity. In an example, there may be one DL-SCH and UL-SCH on a SpCell. In an example, there may be one DL-SCH, zero or one UL-SCH and zero or one RACH for an SCell. A DL-SCH may support receptions using different numerologies and/or TTI duration within a MAC entity. A UL-SCH may also support transmissions using different numerologies and/or TTI duration within the MAC entity.

In an example, a MAC sublayer may support different functions and may control these functions with a control (e.g. 1355 or 1365) element. Functions performed by a MAC entity may comprise mapping between logical channels and transport channels (e.g., in uplink or downlink), multiplexing (e.g. 1352 or 1362) of MAC SDUs from one or different logical channels onto transport blocks (TB) to be delivered to the physical layer on transport channels (e.g., in uplink), demultiplexing (e.g. 1352 or 1362) of MAC SDUs to one or different logical channels from transport blocks (TB) delivered from the physical layer on transport channels (e.g., in downlink), scheduling information reporting (e.g., in uplink), error correction through HARQ in uplink or downlink (e.g. 1363), and logical channel prioritization in uplink (e.g. 1351 or 1361). A MAC entity may handle a random access process (e.g. 1354 or 1364).

FIG. 14 is an example diagram of a RAN architecture comprising one or more base stations. In an example, a protocol stack (e.g. RRC, SDAP, PDCP, RLC, MAC, and PHY) may be supported at a node. A base station (e.g. gNB 120A or 120B) may comprise a base station central unit (CU) (e.g. gNB-CU 1420A or 1420B) and at least one base station distributed unit (DU) (e.g. gNB-DU 1430A, 1430B, 1430C, or 1430D) if a functional split is configured. Upper protocol layers of a base station may be located in a base station CU, and lower layers of the base station may be located in the base station DUs. An F1 interface (e.g. CU-DU interface) connecting a base station CU and base station DUs may be an ideal or non-ideal backhaul. F1-C may provide a control plane connection over an F1 interface, and F1-U may provide a user plane connection over the F1 interface. In an example, an Xn interface may be configured between base station CUs.

In an example, a base station CU may comprise an RRC function, an SDAP layer, and a PDCP layer, and base station DUs may comprise an RLC layer, a MAC layer, and a PHY layer. In an example, various functional split options between a base station CU and base station DUs may be possible by locating different combinations of upper protocol layers (RAN functions) in a base station CU and different combinations of lower protocol layers (RAN functions) in base station DUs. A functional split may support flexibility to move protocol layers between a base station CU and base station DUs depending on service requirements and/or network environments.

In an example, functional split options may be configured per base station, per base station CU, per base station DU, per UE, per bearer, per slice, or with other granularities. In per base station CU split, a base station CU may have a fixed split option, and base station DUs may be configured to match a split option of a base station CU. In per base station DU split, a base station DU may be configured with a different split option, and a base station CU may provide different split options for different base station DUs. In per UE split, a base station (base station CU and at least one base station DUs) may provide different split options for different wireless devices. In per bearer split, different split options may be utilized for different bearers. In per slice splice, different split options may be applied for different slices.

FIG. 15 is an example diagram showing RRC state transitions of a wireless device. In an example, a wireless device may be in at least one RRC state among an RRC connected state (e.g. RRC Connected 1530, RRC_Connected), an RRC idle state (e.g. RRC Idle 1510, RRC_Idle), and/or an RRC inactive state (e.g. RRC Inactive 1520, RRC_Inactive). In an example, in an RRC connected state, a wireless device may have at least one RRC connection with at least one base station (e.g. gNB and/or eNB), which may have a UE context of the wireless device. A UE context (e.g. a wireless device context) may comprise at least one of an access stratum context, one or more radio link configuration parameters, bearer (e.g. data radio bearer (DRB), signaling radio bearer (SRB), logical channel, QoS flow, PDU session, and/or the like) configuration information, security information, PHY/MAC/RLC/PDCP/SDAP layer configuration information, and/or the like configuration information for a wireless device. In an example, in an RRC idle state, a wireless device may not have an RRC connection with a base station, and a UE context of a wireless device may not be stored in a base station. In an example, in an RRC inactive state, a wireless device may not have an RRC connection with a base station. A UE context of a wireless device may be stored in a base station, which may be called as an anchor base station (e.g. last serving base station).

In an example, a wireless device may transition a UE RRC state between an RRC idle state and an RRC connected state in both ways (e.g. connection release 1540 or connection establishment 1550; or connection reestablishment) and/or between an RRC inactive state and an RRC connected state in both ways (e.g. connection inactivation 1570 or connection resume 1580). In an example, a wireless device may transition its RRC state from an RRC inactive state to an RRC idle state (e.g. connection release 1560).

In an example, an anchor base station may be a base station that may keep a UE context (a wireless device context) of a wireless device at least during a time period that a wireless device stays in a RAN notification area (RNA) of an anchor base station, and/or that a wireless device stays in an RRC inactive state. In an example, an anchor base station may be a base station that a wireless device in an RRC inactive state was lastly connected to in a latest RRC connected state or that a wireless device lastly performed an RNA update procedure in. In an example, an RNA may comprise one or more cells operated by one or more base stations. In an example, a base station may belong to one or more RNAs. In an example, a cell may belong to one or more RNAs.

In an example, a wireless device may transition a UE RRC state from an RRC connected state to an RRC inactive state in a base station. A wireless device may receive RNA information from the base station. RNA information may comprise at least one of an RNA identifier, one or more cell identifiers of one or more cells of an RNA, a base station identifier, an IP address of the base station, an AS context identifier of the wireless device, a resume identifier, and/or the like.

In an example, an anchor base station may broadcast a message (e.g. RAN paging message) to base stations of an RNA to reach to a wireless device in an RRC inactive state, and/or the base stations receiving the message from the anchor base station may broadcast and/or multicast another message (e.g. paging message) to wireless devices in their coverage area, cell coverage area, and/or beam coverage area associated with the RNA through an air interface.

In an example, when a wireless device in an RRC inactive state moves into a new RNA, the wireless device may perform an RNA update (RNAU) procedure, which may comprise a random access procedure by the wireless device and/or a UE context retrieve procedure. A UE context retrieve may comprise: receiving, by a base station from a wireless device, a random access preamble; and fetching, by a base station, a UE context of the wireless device from an old anchor base station. Fetching may comprise: sending a retrieve UE context request message comprising a resume identifier to the old anchor base station and receiving a retrieve UE context response message comprising the UE context of the wireless device from the old anchor base station.

In an example embodiment, a wireless device in an RRC inactive state may select a cell to camp on based on at least a on measurement results for one or more cells, a cell where a wireless device may monitor an RNA paging message and/or a core network paging message from a base station. In an example, a wireless device in an RRC inactive state may select a cell to perform a random access procedure to resume an RRC connection and/or to transmit one or more packets to a base station (e.g. to a network). In an example, if a cell selected belongs to a different RNA from an RNA for a wireless device in an RRC inactive state, the wireless device may initiate a random access procedure to perform an RNA update procedure. In an example, if a wireless device in an RRC inactive state has one or more packets, in a buffer, to transmit to a network, the wireless device may initiate a random access procedure to transmit one or more packets to a base station of a cell that the wireless device selects. A random access procedure may be performed with two messages (e.g. 2 stage random access) and/or four messages (e.g. 4 stage random access) between the wireless device and the base station.

In an example embodiment, a base station receiving one or more uplink packets from a wireless device in an RRC inactive state may fetch a UE context of a wireless device by transmitting a retrieve UE context request message for the wireless device to an anchor base station of the wireless device based on at least one of an AS context identifier, an RNA identifier, a base station identifier, a resume identifier, and/or a cell identifier received from the wireless device. In response to fetching a UE context, a base station may transmit a path switch request for a wireless device to a core network entity (e.g. AMF, MME, and/or the like). A core network entity may update a downlink tunnel endpoint identifier for one or more bearers established for the wireless device between a user plane core network entity (e.g. UPF, S-GW, and/or the like) and a RAN node (e.g. the base station), e.g. changing a downlink tunnel endpoint identifier from an address of the anchor base station to an address of the base station.

A gNB may transmit one or more MAC PDUs to a wireless device. In an example, a MAC PDU may be a bit string that is byte aligned (e.g., a multiple of eight bits) in length. In an example, bit strings may be represented by tables in which the most significant bit is the leftmost bit of the first line of the table, and the least significant bit is the rightmost bit on the last line of the table. More generally, the bit string may be read from left to right and then in the reading order of the lines. In an example, the bit order of a parameter field within a MAC PDU is represented with the first and most significant bit in the leftmost bit and the last and least significant bit in the rightmost bit.

In an example, a MAC SDU may be a bit string that is byte aligned (e.g., a multiple of eight bits) in length. In an example, a MAC SDU may be included in a MAC PDU from the first bit onward.

In an example, a MAC CE may be a bit string that is byte aligned (e.g., a multiple of eight bits) in length.

In an example, a MAC subheader may be a bit string that is byte aligned (e.g., a multiple of eight bits) in length. In an example, a MAC subheader may be placed immediately in front of a corresponding MAC SDU, MAC CE, or padding.

In an example, a MAC entity may ignore a value of reserved bits in a DL MAC PDU.

In an example, a MAC PDU may comprise one or more MAC subPDUs. A MAC subPDU of the one or more MAC subPDUs may comprise: a MAC subheader only (including padding); a MAC subheader and a MAC SDU; a MAC subheader and a MAC CE; and/or a MAC subheader and padding. In an example, the MAC SDU may be of variable size. In an example, a MAC subheader may correspond to a MAC SDU, a MAC CE, or padding.

In an example, when a MAC subheader corresponds to a MAC SDU, a variable-sized MAC CE, or padding, the MAC subheader may comprise: an R field with a one bit length; an F field with a one bit length; an LCID field with a multi-bit length; and/or an L field with a multi-bit length.

FIG. 16A shows an example of a MAC subheader with an R field, an F field, an LCID field, and an L field. In the example MAC subheader of FIG. 16A, the LCID field may be six bits in length, and the L field may be eight bits in length. FIG. 16B shows example of a MAC subheader with an R field, a F field, an LCID field, and an L field. In the example MAC subheader of FIG. 16B, the LCID field may be six bits in length, and the L field may be sixteen bits in length.

In an example, when a MAC subheader corresponds to a fixed sized MAC CE or padding, the MAC subheader may comprise: an R field with a two bit length and an LCID field with a multi-bit length. FIG. 16C shows an example of a MAC subheader with an R field and an LCID field. In the example MAC subheader of FIG. 16C, the LCID field may be six bits in length, and the R field may be two bits in length.

FIG. 17A shows an example of a DL MAC PDU. In the example of FIG. 17A, multiple MAC CEs, such as MAC CE 1 and 2, may be placed together. A MAC subPDU comprising a MAC CE may be placed before any MAC subPDU comprising a MAC SDU or a MAC subPDU comprising padding.

FIG. 17B shows an example of a UL MAC PDU. In the example of FIG. 17B, multiple MAC CEs, such as MAC CE 1 and 2, may be placed together. A MAC subPDU comprising a MAC CE may be placed after all MAC subPDUs comprising a MAC SDU. In addition, the MAC subPDU may be placed before a MAC subPDU comprising padding.

In an example, a MAC entity of a gNB may transmit one or more MAC CEs to a MAC entity of a wireless device. FIG. 18 shows an example of multiple LCIDs that may be associated with the one or more MAC CEs. In the example of FIG. 18, the one or more MAC CEs comprise at least one of: a SP ZP CSI-RS Resource Set Activation/Deactivation MAC CE; a PUCCH spatial relation Activation/Deactivation MAC CE; a SP SRS Activation/Deactivation MAC CE; a SP CSI reporting on PUCCH Activation/Deactivation MAC CE; a TCI State Indication for UE-specific PDCCH MAC CE; a TCI State Indication for UE-specific PDSCH MAC CE; an Aperiodic CSI Trigger State Subselection MAC CE; a SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE; a UE contention resolution identity MAC CE; a timing advance command MAC CE; a DRX command MAC CE; a Long DRX command MAC CE; an SCell activation/deactivation MAC CE (1 Octet); an SCell activation/deactivation MAC CE (4 Octet); and/or a duplication activation/deactivation MAC CE. In an example, a MAC CE, such as a MAC CE transmitted by a MAC entity of a gNB to a MAC entity of a wireless device, may have an LCID in the MAC subheader corresponding to the MAC CE. Different MAC CE may have different LCID in the MAC subheader corresponding to the MAC CE. For example, an LCID given by 111011 in a MAC subheader may indicate that a MAC CE associated with the MAC subheader is a long DRX command MAC CE.

In an example, the MAC entity of the wireless device may transmit to the MAC entity of the gNB one or more MAC CEs. FIG. 19 shows an example of the one or more MAC CEs. The one or more MAC CEs may comprise at least one of: a short buffer status report (BSR) MAC CE; a long BSR MAC CE; a C-RNTI MAC CE; a configured grant confirmation MAC CE; a single entry PHR MAC CE; a multiple entry PHR MAC CE; a short truncated BSR; and/or a long truncated BSR. In an example, a MAC CE may have an LCID in the MAC subheader corresponding to the MAC CE. Different MAC CE may have different LCID in the MAC subheader corresponding to the MAC CE. For example, an LCID given by 111011 in a MAC subheader may indicate that a MAC CE associated with the MAC subheader is a short-truncated command MAC CE.

In carrier aggregation (CA), two or more component carriers (CCs) may be aggregated. A wireless device may simultaneously receive or transmit on one or more CCs, depending on capabilities of the wireless device, using the technique of CA. In an example, a wireless device may support CA for contiguous CCs and/or for non-contiguous CCs. CCs may be organized into cells. For example, CCs may be organized into one primary cell (PCell) and one or more secondary cells (SCells).

When configured with CA, a wireless device may have one RRC connection with a network. During an RRC connection establishment/re-establishment/handover, a cell providing NAS mobility information may be a serving cell. During an RRC connection re-establishment/handover procedure, a cell providing a security input may be a serving cell. In an example, the serving cell may denote a PCell. In an example, a gNB may transmit, to a wireless device, one or more messages comprising configuration parameters of a plurality of one or more SCells, depending on capabilities of the wireless device.

When configured with CA, a base station and/or a wireless device may employ an activation/deactivation mechanism of an SCell to improve battery or power consumption of the wireless device. When a wireless device is configured with one or more SCells, a gNB may activate or deactivate at least one of the one or more SCells. Upon configuration of an SCell, the SCell may be deactivated unless an SCell state associated with the SCell is set to “activated” or “dormant”.

In an example, a wireless device may activate/deactivate an SCell in response to receiving an SCell Activation/Deactivation MAC CE.

In an example, a gNB may transmit, to a wireless device, one or more messages comprising an SCell timer (e.g., sCellDeactivationTimer). In an example, a wireless device may deactivate an SCell in response to an expiry of the SCell timer.

When a wireless device receives an SCell Activation/Deactivation MAC CE activating an SCell, the wireless device may activate the SCell. In response to the activating the SCell, the wireless device may perform operations comprising: SRS transmissions on the SCell; CQI/PMI/RI/CRI reporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoring for the SCell; and/or PUCCH transmissions on the SCell.

In an example, in response to the activating the SCell, the wireless device may start or restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the SCell. The wireless device may start or restart the first SCell timer in the slot when the SCell Activation/Deactivation MAC CE activating the SCell has been received. In an example, in response to the activating the SCell, the wireless device may (re-)initialize one or more suspended configured uplink grants of a configured grant Type 1 associated with the SCell according to a stored configuration. In an example, in response to the activating the SCell, the wireless device may trigger PHR.

When a wireless device receives an SCell Activation/Deactivation MAC CE deactivating an activated SCell, the wireless device may deactivate the activated SCell. In an example, when a first SCell timer (e.g., sCellDeactivationTimer) associated with an activated SCell expires, the wireless device may deactivate the activated SCell. In response to the deactivating the activated SCell, the wireless device may stop the first SCell timer associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may clear one or more configured downlink assignments and/or one or more configured uplink grants of a configured uplink grant Type 2 associated with the activated SCell. In an example, in response to the deactivating the activated SCell, the wireless device may: suspend one or more configured uplink grants of a configured uplink grant Type 1 associated with the activated SCell; and/or flush HARQ buffers associated with the activated SCell.

In an example, when an SCell is deactivated, a wireless device may not perform operations comprising: transmitting SRS on the SCell; reporting CQI/PMI/RI/CRI for the SCell; transmitting on UL-SCH on the SCell; transmitting on RACH on the SCell; monitoring at least one first PDCCH on the SCell; monitoring at least one second PDCCH for the SCell; and/or transmitting a PUCCH on the SCell.

In an example, when at least one first PDCCH on an activated SCell indicates an uplink grant or a downlink assignment, a wireless device may restart a first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell. In an example, when at least one second PDCCH on a serving cell (e.g. a PCell or an SCell configured with PUCCH, i.e. PUCCH SCell) scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell, a wireless device may restart the first SCell timer (e.g., sCellDeactivationTimer) associated with the activated SCell.

In an example, when an SCell is deactivated, if there is an ongoing random access procedure on the SCell, a wireless device may abort the ongoing random access procedure on the SCell.

FIG. 20A shows an example of an SCell Activation/Deactivation MAC CE of one octet. A first MAC PDU subheader with a first LCID (e.g., ‘111010’ as shown in FIG. 18) may identify the SCell Activation/Deactivation MAC CE of one octet. The SCell Activation/Deactivation MAC CE of one octet may have a fixed size. The SCell Activation/Deactivation MAC CE of one octet may comprise a single octet. The single octet may comprise a first number of C-fields (e.g. seven) and a second number of R-fields (e.g., one).

FIG. 20B shows an example of an SCell Activation/Deactivation MAC CE of four octets. A second MAC PDU subheader with a second LCID (e.g., ‘111001’ as shown in FIG. 18) may identify the SCell Activation/Deactivation MAC CE of four octets. The SCell Activation/Deactivation MAC CE of four octets may have a fixed size. The SCell Activation/Deactivation MAC CE of four octets may comprise four octets. The four octets may comprise a third number of C-fields (e.g., 31) and a fourth number of R-fields (e.g., 1).

In FIG. 20A and/or FIG. 20B, a C_(i) field may indicate an activation/deactivation status of an SCell with an SCell index i if an SCell with SCell index i is configured. In an example, when the C_(i) field is set to one, an SCell with an SCell index i may be activated. In an example, when the C_(i) field is set to zero, an SCell with an SCell index i may be deactivated. In an example, if there is no SCell configured with SCell index i, the wireless device may ignore the C_(i) field. In FIG. 20A and FIG. 20B, an R field may indicate a reserved bit. The R field may be set to zero.

When configured with CA, a base station and/or a wireless device may employ a hibernation mechanism for an SCell to improve battery or power consumption of the wireless device and/or to improve latency of SCell activation/addition. When the wireless device hibernates the SCell, the SCell may be transitioned into a dormant state. In response to the SCell being transitioned into a dormant state, the wireless device may: stop transmitting SRS on the SCell; report CQI/PMI/RI/PTI/CRI for the SCell according to a periodicity configured for the SCell in a dormant state; not transmit on UL-SCH on the SCell; not transmit on RACH on the SCell; not monitor the PDCCH on the SCell; not monitor the PDCCH for the SCell; and/or not transmit PUCCH on the SCell. In an example, reporting CSI for an SCell and not monitoring the PDCCH on/for the SCell, when the SCell is in a dormant state, may provide the base station an always-updated CSI for the SCell. With the always-updated CSI, the base station may employ a quick and/or accurate channel adaptive scheduling on the SCell once the SCell is transitioned back into active state, thereby speeding up the activation procedure of the SCell. In an example, reporting CSI for the SCell and not monitoring the PDCCH on/for the SCell, when the SCell is in dormant state, may improve battery or power consumption of the wireless device, while still providing the base station timely and/or accurate channel information feedback. In an example, a PCell/PSCell and/or a PUCCH secondary cell may not be configured or transitioned into dormant state.

When configured with one or more SCells, a gNB may activate, hibernate, or deactivate at least one of the one or more SCells. In an example, a gNB may transmit one or more RRC messages comprising parameters indicating at least one SCell being set to an active state, a dormant state, or an inactive state, to a wireless device.

In an example, when an SCell is in an active state, the wireless device may perform: SRS transmissions on the SCell; CQI/PMI/RI/CRI reporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoring for the SCell; and/or PUCCH/SPUCCH transmissions on the SCell.

In an example, when an SCell is in an inactive state, the wireless device may: not transmit SRS on the SCell; not report CQI/PMI/RI/CRI for the SCell; not transmit on UL-SCH on the SCell; not transmit on RACH on the SCell; not monitor PDCCH on the SCell; not monitor PDCCH for the SCell; and/or not transmit PUCCH/SPUCCH on the SCell.

In an example, when an SCell is in a dormant state, the wireless device may: not transmit SRS on the SCell; report CQI/PMI/RI/CRI for the SCell; not transmit on UL-SCH on the SCell; not transmit on RACH on the SCell; not monitor PDCCH on the SCell; not monitor PDCCH for the SCell; and/or not transmit PUCCH/SPUCCH on the SCell.

When configured with one or more SCells, a gNB may activate, hibernate, or deactivate at least one of the one or more SCells. In an example, a gNB may transmit one or more MAC control elements comprising parameters indicating activation, deactivation, or hibernation of at least one SCell to a wireless device.

In an example, a gNB may transmit a first MAC CE (e.g., activation/deactivation MAC CE, as shown in FIG. 20A or FIG. 20B) indicating activation or deactivation of at least one SCell to a wireless device. In FIG. 20A and/or FIG. 20B, a C_(i) field may indicate an activation/deactivation status of an SCell with an SCell index i if an SCell with SCell index i is configured. In an example, when the C_(i) field is set to one, an SCell with an SCell index i may be activated. In an example, when the C_(i) field is set to zero, an SCell with an SCell index i may be deactivated. In an example, if there is no SCell configured with SCell index i, the wireless device may ignore the C_(i) field. In FIG. 20A and FIG. 20B, an R field may indicate a reserved bit. In an example, the R field may be set to zero.

In an example, a gNB may transmit a second MAC CE (e.g., hibernation MAC CE) indicating activation or hibernation of at least one SCell to a wireless device. In an example, the second MAC CE may be associated with a second LCID different from a first LCID of the first MAC CE (e.g., activation/deactivation MAC CE). In an example, the second MAC CE may have a fixed size. In an example, the second MAC CE may consist of a single octet containing seven C-fields and one R-field. FIG. 21A shows an example of the second MAC CE with a single octet. In another example, the second MAC CE may consist of four octets containing 31 C-fields and one R-field. FIG. 21B shows an example of the second MAC CE with four octets. In an example, the second MAC CE with four octets may be associated with a third LCID different from the second LCID for the second MAC CE with a single octet, and/or the first LCID for activation/deactivation MAC CE. In an example, when there is no SCell with a serving cell index greater than 7, the second MAC CE of one octet may be applied, otherwise the second MAC CE of four octets may be applied.

In an example, when the second MAC CE is received, and the first MAC CE is not received, C_(i) may indicate a dormant/activated status of an SCell with SCell index i if there is an SCell configured with SCell index i, otherwise the MAC entity may ignore the C_(i) field. In an example, when C_(i) is set to “1”, the wireless device may transition an SCell associated with SCell index i into a dormant state. In an example, when C_(i) is set to “0”, the wireless device may activate an SCell associated with SCell index i. In an example, when C_(i) is set to “0” and the SCell with SCell index i is in a dormant state, the wireless device may activate the SCell with SCell index i. In an example, when C_(i) is set to “0” and the SCell with SCell index i is not in a dormant state, the wireless device may ignore the C_(i) field.

In an example, when both the first MAC CE (activation/deactivation MAC CE) and the second MAC CE (hibernation MAC CE) are received, two C_(i) fields of the two MAC CEs may indicate possible state transitions of the SCell with SCell index i if there is an SCell configured with SCell index i, otherwise the MAC entity may ignore the C_(i) fields. In an example, the C_(i) fields of the two MAC CEs may be interpreted according to FIG. 21C. FIG. 22 shows an example of SCell state transitions based on activation/deactivation MAC CE and/or hibernation MAC CE.

When configured with one or more SCells, a gNB may activate, hibernate, or deactivate at least one of the one or more SCells. In an example, a MAC entity of a gNB and/or a wireless device may maintain an SCell deactivation timer (e.g., sCellDeactivationTimer) per configured SCell (except the SCell configured with PUCCH/SPUCCH, if any) and deactivate the associated SCell upon its expiry.

In an example, a MAC entity of a gNB and/or a wireless device may maintain an SCell hibernation timer (e.g., sCellHibernationTimer) per configured SCell (except the SCell configured with PUCCH/SPUCCH, if any) and hibernate the associated SCell upon the SCell hibernation timer expiry if the SCell is in active state. In an example, when both the SCell deactivation timer and the SCell hibernation timer are configured, the SCell hibernation timer may take priority over the SCell deactivation timer. In an example, when both the SCell deactivation timer and the SCell hibernation timer are configured, a gNB and/or a wireless device may ignore the SCell deactivation timer regardless of the SCell deactivation timer expiry.

In an example, a MAC entity of a gNB and/or a wireless device may maintain a dormant SCell deactivation timer (e.g., dormantSCellDeactivationTimer) per configured SCell (except the SCell configured with PUCCH/SPUCCH, if any), and deactivate the associated SCell upon the dormant SCell deactivation timer expiry if the SCell is in dormant state.

FIG. 23 shows an example of SCell state transitions based on a first SCell timer (e.g., an SCell deactivation timer or sCellDeactivationTimer), a second SCell timer (e.g., an SCell hibernation timer or sCellHibernationTimer), and/or a third SCell timer (e.g., a dormant SCell deactivation timer or dormantSCellDeactivationTimer).

In an example, when a MAC entity of a wireless device is configured with an activated SCell upon SCell configuration, the MAC entity may activate the SCell. In an example, when a MAC entity of a wireless device receives a MAC CE(s) activating an SCell, the MAC entity may activate the SCell. In an example, the MAC entity may start or restart the SCell deactivation timer associated with the SCell in response to activating the SCell. In an example, the MAC entity may start or restart the SCell hibernation timer (if configured) associated with the SCell in response to activating the SCell. In an example, the MAC entity may trigger PHR procedure in response to activating the SCell.

In an example, when a MAC entity of a wireless device receives a MAC CE(s) indicating deactivating an SCell, the MAC entity may deactivate the SCell. In an example, in response to receiving the MAC CE(s), the MAC entity may: deactivate the SCell; stop an SCell deactivation timer associated with the SCell; and/or flush all HARQ buffers associated with the SCell.

In an example, when an SCell deactivation timer associated with an activated SCell expires and an SCell hibernation timer is not configured, the MAC entity may: deactivate the SCell; stop the SCell deactivation timer associated with the SCell; and/or flush all HARQ buffers associated with the SCell.

In an example, when a first PDCCH on an activated SCell indicates an uplink grant or downlink assignment, or a second PDCCH on a serving cell scheduling an activated SCell indicates an uplink grant or a downlink assignment for the activated SCell, or a MAC PDU is transmitted in a configured uplink grant or received in a configured downlink assignment, the MAC entity may: restart the SCell deactivation timer associated with the SCell; and/or restart the SCell hibernation timer associated with the SCell if configured. In an example, when an SCell is deactivated, an ongoing random access procedure on the SCell may be aborted.

In an example, when a MAC entity is configured with an SCell associated with an SCell state set to dormant state upon the SCell configuration, or when the MAC entity receives MAC CE(s) indicating transitioning the SCell into a dormant state, the MAC entity may: transition the SCell into a dormant state; transmit one or more CSI reports for the SCell; stop an SCell deactivation timer associated with the SCell; stop an SCell hibernation timer associated with the SCell if configured; start or restart a dormant SCell deactivation timer associated with the SCell; and/or flush all HARQ buffers associated with the SCell. In an example, when the SCell hibernation timer associated with the activated SCell expires, the MAC entity may: hibernate the SCell; stop the SCell deactivation timer associated with the SCell; stop the SCell hibernation timer associated with the SCell; and/or flush all HARQ buffers associated with the SCell. In an example, when a dormant SCell deactivation timer associated with a dormant SCell expires, the MAC entity may: deactivate the SCell; and/or stop the dormant SCell deactivation timer associated with the SCell. In an example, when an SCell is in dormant state, ongoing random access procedure on the SCell may be aborted.

FIG. 24 shows an example of a CSI-RS that may be mapped in time and frequency domains. Each square shown in FIG. 24 may represent a resource block within a bandwidth of a cell. Each resource block may comprise a number of subcarriers. A cell may have a bandwidth comprising a number of resource blocks. A base station (e.g., a gNB in NR) may transmit one or more Radio Resource Control (RRC) messages comprising CSI-RS resource configuration parameters for one or more CSI-RS. One or more of the following parameters may be configured by higher layer signaling for each CSI-RS resource configuration: CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and RE locations in a subframe), CSI-RS subframe configuration (e.g., subframe location, offset, and periodicity in a radio frame), CSI-RS power parameter, CSI-RS sequence parameter, CDM type parameter, frequency density, transmission comb, QCL parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resource parameters.

FIG. 24 shows three beams that may be configured for a wireless device, e.g., in a wireless device-specific configuration. Any number of additional beams (e.g., represented by the column of blank squares) or fewer beams may be included. Beam 1 may be allocated with CSI-RS 1 that may be transmitted in some subcarriers in a resource block (RB) of a first symbol. Beam 2 may be allocated with CSI-RS 2 that may be transmitted in some subcarriers in a RB of a second symbol. Beam 3 may be allocated with CSI-RS 3 that may be transmitted in some subcarriers in an RB of a third symbol. All subcarriers in a RB may not necessarily be used for transmitting a particular CSI-RS (e.g., CSI-RS 1) on an associated beam (e.g., beam 1) for that CSI-RS. By using frequency division multiplexing (FDM), other subcarriers, not used for beam 1 for the wireless device in the same RB, may be used for other CSI-RS transmissions associated with a different beam for other wireless devices. Additionally or alternatively, by using time domain multiplexing (TDM), beams used for a wireless device may be configured such that different beams (e.g., beam 1, beam 2, and beam 3) for the wireless device may be transmitted using some symbols different from beams of other wireless devices.

Beam management may use a device-specific configured CSI-RS. In a beam management procedure, a wireless device may monitor a channel quality of a beam pair link comprising a transmitting beam by a base station (e.g., a gNB in NR) and a receiving beam by the wireless device (e.g., a UE). When multiple CSI-RSs associated with multiple beams are configured, a wireless device may monitor multiple beam pair links between the base station and the wireless device.

A wireless device may transmit one or more beam management reports to a base station. A beam management report may indicate one or more beam pair quality parameters, comprising, e.g., one or more beam identifications, RSRP, PMI, CQI, and/or RI, of a subset of configured beams.

FIG. 25 shows examples of three beam management procedures, P1, P2, and P3. Procedure P1 may be used to enable a wireless device measurement on different transmit (Tx) beams of a TRP (or multiple TRPs), e.g., to support a selection of Tx beams and/or wireless device receive (Rx) beam(s) (shown as ovals in the top row and bottom row, respectively, of P1). Beamforming at a TRP (or multiple TRPs) may include, e.g., an intra-TRP and/or inter-TRP Tx beam sweep from a set of different beams (shown, in the top rows of P1 and P2, as ovals rotated in a counter-clockwise direction indicated by the dashed arrow). Beamforming at a wireless device 1901, may include, e.g., a wireless device Rx beam sweep from a set of different beams (shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwise direction indicated by the dashed arrow). Procedure P2 may be used to enable a wireless device measurement on different Tx beams of a TRP (or multiple TRPs) (shown, in the top row of P2, as ovals rotated in a counter-clockwise direction indicated by the dashed arrow), e.g., which may change inter-TRP and/or intra-TRP Tx beam(s). Procedure P2 may be performed, e.g., on a smaller set of beams for beam refinement than in procedure P1. P2 may be a particular example of P1. Procedure P3 may be used to enable a wireless device measurement on the same Tx beam (shown as oval in P3), e.g., to change a wireless device Rx beam if the wireless device uses beamforming.

A wireless device (e.g., a UE) and/or a base station (e.g., a gNB) may trigger a beam failure recovery mechanism. The wireless device may trigger a beam failure recovery (BFR) request transmission, e.g., if a beam failure event occurs. A beam failure event may include, e.g., a determination that a quality of beam pair link(s) of an associated control channel is unsatisfactory. A determination of an unsatisfactory quality of beam pair link(s) of an associated channel may be based on the quality falling below a threshold and/or an expiration of a timer.

The wireless device may measure a quality of beam pair link(s) using one or more reference signals (RS). One or more SS blocks, one or more CSI-RS resources, and/or one or more demodulation reference signals (DM-RSs) of a PBCH may be used as a RS for measuring a quality of a beam pair link. Each of the one or more CSI-RS resources may be associated with a CSI-RS resource index (CRI). A quality of a beam pair link may be based on one or more of an RSRP value, reference signal received quality (RSRQ) value, and/or CSI value measured on RS resources. The base station may indicate that an RS resource, e.g., that may be used for measuring a beam pair link quality, is quasi-co-located (QCLed) with one or more DM-RSs of a control channel. The RS resource and the DM-RSs of the control channel may be QCLed when the channel characteristics from a transmission via an RS to the wireless device, and the channel characteristics from a transmission via a control channel to the wireless device, are similar or the same under a configured criterion.

A base station and/or a wireless device may perform a downlink L1/L2 beam management procedure. One or more downlink L1/L2 beam management procedures may be performed within one or multiple TRPs, such as shown in FIG. 26A and FIG. 26B, respectively.

FIG. 26A shows an example of a beam failure event involving a single TRP. A single TRP such as at a base station 2601 may transmit, to a wireless device 2602, a first beam 2603 and a second beam 2604. A beam failure event may occur if, e.g., a serving beam, such as the second beam 2604, is blocked by a moving vehicle 2605 or other obstruction (e.g., building, tree, land, or any object) and configured beams (e.g., the first beam 2603 and/or the second beam 2604), including the serving beam, are received from the single TRP. The wireless device 2602 may trigger a mechanism to recover from beam failure when a beam failure occurs.

FIG. 26B shows an example of a beam failure event involving multiple TRPs. Multiple TRPs, such as at a first base station 2606 and at a second base station 2609, may transmit, to a wireless device 2608, a first beam 2607 (e.g., from the first base station 2606) and a second beam 2610 (e.g., from the second base station 2609). A beam failure event may occur when, e.g., a serving beam, such as the second beam 2610, is blocked by a moving vehicle 2611 or other obstruction (e.g., building, tree, land, or any object) and configured beams (e.g., the first beam 2607 and/or the second beam 2610) are received from multiple TRPs. The wireless device 2008 may trigger a mechanism to recover from beam failure when a beam failure occurs.

A wireless device may monitor a PDCCH, such as a New Radio PDCCH (NR-PDCCH), on M beam pair links simultaneously, where M>1 and the maximum value of M may depend at least on the wireless device capability. Such monitoring may increase robustness against beam pair link blocking. A base station may transmit, and the wireless device may receive, one or more messages configured to cause the wireless device to monitor NR-PDCCH on different beam pair link(s) and/or in different NR-PDCCH OFDM symbol.

A base station may transmit higher layer signaling, and/or a MAC control element (MAC CE), that may comprise parameters related to a wireless device Rx beam setting for monitoring NR-PDCCH on multiple beam pair links. A base station may transmit one or more indications of a spatial QCL assumption between a first DL RS antenna port(s) and a second DL RS antenna port(s). The first DL RS antenna port(s) may be for one or more of a cell-specific CSI-RS, device-specific CSI-RS, SS block, PBCH with DM-RSs of PBCH, and/or PBCH without DM-RSs of PBCH. The second DL RS antenna port(s) may be for demodulation of a DL control channel. Signaling for a beam indication for a NR-PDCCH (e.g., configuration to monitor NR-PDCCH) may be via MAC CE signaling, RRC signaling, DCI signaling, or specification-transparent and/or an implicit method, and any combination thereof.

For reception of unicast DL data channel, a base station may indicate spatial QCL parameters between DL RS antenna port(s) and DM-RS antenna port(s) of DL data channel. A base station may transmit DCI (e.g., downlink grants) comprising information indicating the RS antenna port(s). The information may indicate the RS antenna port(s) which may be QCLed with DM-RS antenna port(s). A different set of DM-RS antenna port(s) for the DL data channel may be indicated as a QCL with a different set of RS antenna port(s).

If a base station transmits a signal indicating a spatial QCL parameters between CSI-RS and DM-RS for PDCCH, a wireless device may use CSI-RSs QCLed with DM-RS for a PDCCH to monitor beam pair link quality. If a beam failure event occurs, the wireless device may transmit a beam failure recovery request, such as by a determined configuration.

If a wireless device transmits a beam failure recovery request, e.g., via an uplink physical channel or signal, a base station may detect that there is a beam failure event, for the wireless device, by monitoring the uplink physical channel or signal. The base station may initiate a beam recovery mechanism to recover the beam pair link for transmitting PDCCH between the base station and the wireless device. The base station may transmit one or more control signals, to the wireless device, e.g., after or in response to receiving the beam failure recovery request. A beam recovery mechanism may be, e.g., an L1 scheme, or a higher layer scheme.

A base station may transmit one or more messages comprising, e.g., configuration parameters of an uplink physical channel and/or a signal for transmitting a beam failure recovery request. The uplink physical channel and/or signal may be based on at least one of the following: a non-contention based PRACH (e.g., a beam failure recovery PRACH or BFR-PRACH), which may use a resource orthogonal to resources of other PRACH transmissions; a PUCCH (e.g., beam failure recovery PUCCH or BFR-PUCCH); and/or a contention-based PRACH resource. Combinations of these candidate signal and/or channels may be configured by a base station.

A gNB may respond a confirmation message to a UE after receiving one or multiple BFR request. The confirmation message may include the CRI associated with the candidate beam the UE indicates in the one or multiple BFR request. The confirmation message may be a L1 control information.

FIG. 27 shows DCI formats for an example of 20 MHz FDD operation with 2 Tx antennas at the base station and no carrier aggregation in an LTE system. In a NR system, the DCI formats may comprise at least one of: DCI format 0_0/0_1 indicating scheduling of PUSCH in a cell; DCI format 1_0/1_1 indicating scheduling of PDSCH in a cell; DCI format 2_0 notifying a group of UEs of slot format; DCI format 2_1 notifying a group of UEs of PRB(s) and OFDM symbol(s) where a UE may assume no transmission is intended for the UE; DCI format 2_2 indicating transmission of TPC commands for PUCCH and PUSCH; and/or DCI format 2_3 indicating transmission of a group of TPC commands for SRS transmission by one or more UEs. In an example, a gNB may transmit a DCI via a PDCCH for scheduling decision and power-control commends. More specifically, the DCI may comprise at least one of: downlink scheduling assignments, uplink scheduling grants, power-control commands. The downlink scheduling assignments may comprise at least one of: PDSCH resource indication, transport format, HARQ information, and control information related to multiple antenna schemes, a command for power control of the PUCCH used for transmission of ACK/NACK in response to downlink scheduling assignments. The uplink scheduling grants may comprise at least one of: PUSCH resource indication, transport format, and HARQ related information, a power control command of the PUSCH.

In an example, the different types of control information correspond to different DCI message sizes. For example, supporting spatial multiplexing with noncontiguous allocation of RBs in the frequency domain may require a larger scheduling message in comparison with an uplink grant allowing for frequency-contiguous allocation only. The DCI may be categorized into different DCI formats, where a format corresponds to a certain message size and usage.

In an example, a UE may monitor one or more PDCCH candidates to detect one or more DCI with one or more DCI format. The one or more PDCCH may be transmitted in common search space or UE-specific search space. A UE may monitor PDCCH with only a limited set of DCI format, to save power consumption. For example, a normal UE may not be required to detect a DCI with DCI format 6 which is used for an eMTC UE. The more DCI format to be detected, the more power be consumed at the UE.

In an example, the one or more PDCCH candidates that a UE monitors may be defined in terms of PDCCH UE-specific search spaces. A PDCCH UE-specific search space at CCE aggregation level L∈{1, 2, 4, 8} may be defined by a set of PDCCH candidates for CCE aggregation level L. In an example, for a DCI format, a UE may be configured per serving cell by one or more higher layer parameters a number of PDCCH candidates per CCE aggregation level L.

In an example, in non-DRX mode operation, a UE may monitor one or more PDCCH candidate in control resource set q according to a periodicity of W_(PDCCHq) symbols that may be configured by one or more higher layer parameters for control resource set q.

In an example, if a UE is configured with higher layer parameter, e.g., cif-InSchedulingCell, the carrier indicator field value may correspond to cif-InSchedulingCell.

In an example, for the serving cell on which a UE may monitor one or more PDCCH candidate in a UE-specific search space, if the UE is not configured with a carrier indicator field, the UE may monitor the one or more PDCCH candidates without carrier indicator field. In an example, for the serving cell on which a UE may monitor one or more PDCCH candidates in a UE-specific search space, if a UE is configured with a carrier indicator field, the UE may monitor the one or more PDCCH candidates with carrier indicator field.

In an example, a UE may not monitor one or more PDCCH candidates on a secondary cell if the UE is configured to monitor one or more PDCCH candidates with carrier indicator field corresponding to that secondary cell in another serving cell. For example, for the serving cell on which the UE may monitor one or more PDCCH candidates, the UE may monitor the one or more PDCCH candidates at least for the same serving cell.

In an example, the information in the DCI formats used for downlink scheduling may be organized into different groups, with the field present varying between the DCI formats, including at least one of: resource information, consisting of: carrier indicator (0 or 3 bits), RB allocation; HARQ process number; MCS, NDI, and RV (for the first TB); MCS, NDI and RV (for the second TB); MIMO related information; PDSCH resource-element mapping and QCI; Downlink assignment index (DAI); TPC for PUCCH; SRS request (Ibit), triggering one-shot SRS transmission; ACK/NACK offset; DCI format 0/1A indication, used to differentiate between DCI format 1A and 0; and padding if necessary. The MIMO related information may comprise at least one of: PMI, precoding information, transport block swap flag, power offset between PDSCH and reference signal, reference-signal scrambling sequence, number of layers, and/or antenna ports for the transmission.

In an example, the information in the DCI formats used for uplink scheduling may be organized into different groups, with the field present varying between the DCI formats, including at least one of: resource information, consisting of: carrier indicator, resource allocation type, RB allocation; MCS, NDI (for the first TB); MCS, NDI (for the second TB); phase rotation of the uplink DMRS; precoding information; CSI request, requesting an aperiodic CSI report; SRS request (2 bit), used to trigger aperiodic SRS transmission using one of up to three preconfigured settings; uplink index/DAI; TPC for PUSCH; DCI format 0/1A indication; and padding if necessary.

In an example, a gNB may perform CRC scrambling for a DCI, before transmitting the DCI via a PDCCH. The gNB may perform CRC scrambling by bit-wise addition (or Modulo-2 addition or exclusive OR (XOR) operation) of multiple bits of at least one wireless device identifier (e.g., C-RNTI, CS-RNTI, TPC-CS-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, SP CSI C-RNTI, SRS-TPC-RNTI, INT-RNTI, SFI-RNTI, P-RNTI, SI-RNTI, RA-RNTI, and/or MCS-C-RNTI) with the CRC bits of the DCI. The wireless device may check the CRC bits of the DCI, when detecting the DCI. The wireless device may receive the DCI when the CRC is scrambled by a sequence of bits that is the same as the at least one wireless device identifier.

In a NR system, in order to support wide bandwidth operation, a gNB may transmit one or more PDCCH in different control resource sets. A gNB may transmit one or more RRC message comprising configuration parameters of one or more control resource sets. At least one of the one or more control resource sets may comprise at least one of: a first OFDM symbol; a number of consecutive OFDM symbols; a set of resource blocks; a CCE-to-REG mapping; and a REG bundle size, in case of interleaved CCE-to-REG mapping.

A base station (gNB) may configure a wireless device (UE) with uplink (UL) bandwidth parts (BWPs) and downlink (DL) BWPs to enable bandwidth adaptation (BA) on a PCell. If carrier aggregation is configured, the gNB may further configure the UE with at least DL BWP(s) (i.e., there may be no UL BWPs in the UL) to enable BA on an SCell. For the PCell, an initial active BWP may be a first BWP used for initial access. For the SCell, a first active BWP may be a second BWP configured for the UE to operate on the SCell upon the SCell being activated.

In paired spectrum (e.g. FDD), a gNB and/or a UE may independently switch a DL BWP and an UL BWP. In unpaired spectrum (e.g. TDD), a gNB and/or a UE may simultaneously switch a DL BWP and an UL BWP.

In an example, a gNB and/or a UE may switch a BWP between configured BWPs by means of a DCI or a BWP inactivity timer. When the BWP inactivity timer is configured for a serving cell, the gNB and/or the UE may switch an active BWP to a default BWP in response to an expiry of the BWP inactivity timer associated with the serving cell. The default BWP may be configured by the network.

In an example, for FDD systems, when configured with BA, one UL BWP for each uplink carrier and one DL BWP may be active at a time in an active serving cell. In an example, for TDD systems, one DL/UL BWP pair may be active at a time in an active serving cell. Operating on the one UL BWP and the one DL BWP (or the one DL/UL pair) may improve UE battery consumption. BWPs other than the one active UL BWP and the one active DL BWP that the UE may work on may be deactivated. On deactivated BWPs, the UE may: not monitor PDCCH; and/or not transmit on PUCCH, PRACH, and UL-SCH.

In an example, a serving cell may be configured with at most a first number (e.g., four) of BWPs. In an example, for an activated serving cell, there may be one active BWP at any point in time.

In an example, a BWP switching for a serving cell may be used to activate an inactive BWP and deactivate an active BWP at a time. In an example, the BWP switching may be controlled by a PDCCH indicating a downlink assignment or an uplink grant. In an example, the BWP switching may be controlled by a BWP inactivity timer (e.g., bwp-InactivityTimer). In an example, the BWP switching may be controlled by a MAC entity in response to initiating a Random Access procedure. Upon addition of an SpCell or activation of an SCell, one BWP may be initially active without receiving a PDCCH indicating a downlink assignment or an uplink grant. The active BWP for a serving cell may be indicated by RRC and/or PDCCH. In an example, for unpaired spectrum, a DL BWP may be paired with a UL BWP, and BWP switching may be common for both UL and DL.

FIG. 28 shows an example of BWP switching on an SCell. In an example, a UE may receive RRC message comprising parameters of a SCell and one or more BWP configuration associated with the SCell. The RRC message may comprise: RRC connection reconfiguration message (e.g., RRCReconfiguration); RRC connection reestablishment message (e.g., RRCRestablishment); and/or RRC connection setup message (e.g., RRCSetup). Among the one or more BWPs, at least one BWP may be configured as the first active BWP (e.g., BWP 1 in FIG. 28), one BWP as the default BWP (e.g., BWP 0 in FIG. 28). The UE may receive a MAC CE to activate the SCell at n^(th) slot. The UE may start a scell deactivation timer (e.g., sCellDeactivationTimer), and start CSI related actions for the SCell, and/or start CSI related actions for the first active BWP of the SCell. The UE may start monitoring a PDCCH on BWP 1 in response to activating the SCell.

In an example, the UE may start restart a BWP inactivity timer (e.g., bwp-InactivityTimer) at m^(th) slot in response to receiving a DCI indicating DL assignment on BWP 1. The UE may switch back to the default BWP (e.g., BWP 0) as an active BWP when the BWP inactivity timer expires, at s^(th) slot. The UE may deactivate the SCell and/or stop the BWP inactivity timer when the sCellDeactivationTimer expires.

Employing the BWP inactivity timer may further reduce UE's power consumption when the UE is configured with multiple cells with each cell having wide bandwidth (e.g., 1 GHz). The UE may only transmit on or receive from a narrow-bandwidth BWP (e.g., 5 MHz) on the PCell or SCell when there is no activity on an active BWP.

In an example, a MAC entity may apply normal operations on an active BWP for an activated serving cell configured with a BWP comprising: transmitting on UL-SCH; transmitting on RACH; monitoring a PDCCH; transmitting PUCCH; receiving DL-SCH; and/or (re-) initializing any suspended configured uplink grants of configured grant Type 1 according to a stored configuration, if any.

In an example, on an inactive BWP for each activated serving cell configured with a BWP, a MAC entity may: not transmit on UL-SCH; not transmit on RACH; not monitor a PDCCH; not transmit PUCCH; not transmit SRS, not receive DL-SCH; clear any configured downlink assignment and configured uplink grant of configured grant Type 2; and/or suspend any configured uplink grant of configured Type 1.

In an example, if a MAC entity receives a PDCCH for a BWP switching of a serving cell while a Random Access procedure associated with this serving cell is not ongoing, a UE may perform the BWP switching to a BWP indicated by the PDCCH.

In an example, if a bandwidth part indicator field is configured in DCI format 1_1, the bandwidth part indicator field value may indicate the active DL BWP, from the configured DL BWP set, for DL receptions. In an example, if a bandwidth part indicator field is configured in DCI format 0_1, the bandwidth part indicator field value may indicate the active UL BWP, from the configured UL BWP set, for UL transmissions.

In an example, for a primary cell, a UE may be provided by a higher layer parameter Default-DL-BWP a default DL BWP among the configured DL BWPs. If a UE is not provided a default DL BWP by the higher layer parameter Default-DL-BWP, the default DL BWP is the initial active DL BWP.

In an example, a UE may be provided by higher layer parameter bwp-InactivityTimer, a timer value for the primary cell. If configured, the UE may increment the timer, if running, every interval of 1 millisecond for frequency range 1 or every 0.5 milliseconds for frequency range 2 if the UE may not detect a DCI format 1_1 for paired spectrum operation or if the UE may not detect a DCI format 1_1 or DCI format 0_1 for unpaired spectrum operation during the interval.

In an example, if a UE is configured for a secondary cell with higher layer parameter Default-DL-BWP indicating a default DL BWP among the configured DL BWPs and the UE is configured with higher layer parameter bwp-InactivityTimer indicating a timer value, the UE procedures on the secondary cell may be same as on the primary cell using the timer value for the secondary cell and the default DL BWP for the secondary cell.

In an example, if a UE is configured by higher layer parameter Active-BWP-DL-SCell a first active DL BWP and by higher layer parameter Active-BWP-UL-SCell a first active UL BWP on a secondary cell or carrier, the UE may use the indicated DL BWP and the indicated UL BWP on the secondary cell as the respective first active DL BWP and first active UL BWP on the secondary cell or carrier.

In an example, a wireless device may transmit one or more uplink control information (UCI) via one or more PUCCH resources to a base station. The one or more UCI may comprise at least one of: HARQ-ACK information; scheduling request (SR); and/or CSI report. In an example, a PUCCH resource may be identified by at least: frequency location (e.g., starting PRB); and/or a PUCCH format associated with initial cyclic shift of a base sequence and time domain location (e.g., starting symbol index). In an example, a PUCCH format may be PUCCH format 0, PUCCH format 1, PUCCH format 2, PUCCH format 3, or PUCCH format 4. A PUCCH format 0 may have a length of 1 or 2 OFDM symbols and be less than or equal to 2 bits. A PUCCH format 1 may occupy a number between 4 and 14 of OFDM symbols and be less than or equal to 2 bits. A PUCCH format 2 may occupy 1 or 2 OFDM symbols and be greater than 2 bits. A PUCCH format 3 may occupy a number between 4 and 14 of OFDM symbols and be greater than 2 bits. A PUCCH format 4 may occupy a number between 4 and 14 of OFDM symbols and be greater than 2 bits. The PUCCH resource may be configured on a PCell, or a PUCCH secondary cell.

In an example, when configured with multiple uplink BWPs, a base station may transmit to a wireless device, one or more RRC messages comprising configuration parameters of one or more PUCCH resource sets (e.g., at most 4 sets) on an uplink BWP of the multiple uplink BWPs. Each PUCCH resource set may be configured with a PUCCH resource set index, a list of PUCCH resources with each PUCCH resource being identified by a PUCCH resource identifier (e.g., pucch-Resourceid), and/or a maximum number of UCI information bits a wireless device may transmit using one of the plurality of PUCCH resources in the PUCCH resource set.

In an example, when configured with one or more PUCCH resource sets, a wireless device may select one of the one or more PUCCH resource sets based on a total bit length of UCI information bits (e.g., HARQ-ARQ bits, SR, and/or CSI) the wireless device will transmit. In an example, when the total bit length of UCI information bits is less than or equal to 2, the wireless device may select a first PUCCH resource set with the PUCCH resource set index equal to “0”. In an example, when the total bit length of UCI information bits is greater than 2 and less than or equal to a first configured value, the wireless device may select a second PUCCH resource set with the PUCCH resource set index equal to “1”. In an example, when the total bit length of UCI information bits is greater than the first configured value and less than or equal to a second configured value, the wireless device may select a third PUCCH resource set with the PUCCH resource set index equal to “2”. In an example, when the total bit length of UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1706), the wireless device may select a fourth PUCCH resource set with the PUCCH resource set index equal to “3”.

In an example, a wireless device may determine, based on a number of uplink symbols of UCI transmission and a number of UCI bits, a PUCCH format from a plurality of PUCCH formats comprising PUCCH format 0, PUCCH format 1, PUCCH format 2, PUCCH format 3 and/or PUCCH format 4. In an example, the wireless device may transmit UCI in a PUCCH using PUCCH format 0 if the transmission is over 1 symbol or 2 symbols and the number of HARQ-ACK information bits with positive or negative SR (HARQ-ACK/SR bits) is 1 or 2. In an example, the wireless device may transmit UCI in a PUCCH using PUCCH format 1 if the transmission is over 4 or more symbols and the number of HARQ-ACK/SR bits is 1 or 2. In an example, the wireless device may transmit UCI in a PUCCH using PUCCH format 2 if the transmission is over 1 symbol or 2 symbols and the number of UCI bits is more than 2. In an example, the wireless device may transmit UCI in a PUCCH using PUCCH format 3 if the transmission is over 4 or more symbols, the number of UCI bits is more than 2 and PUCCH resource does not include an orthogonal cover code. In an example, the wireless device may transmit UCI in a PUCCH using PUCCH format 4 if the transmission is over 4 or more symbols, the number of UCI bits is more than 2 and the PUCCH resource includes an orthogonal cover code.

In an example, in order to transmit HARQ-ACK information on a PUCCH resource, a wireless device may determine the PUCCH resource from a PUCCH resource set. The PUCCH resource set may be determined as mentioned above. The wireless device may determine the PUCCH resource based on a PUCCH resource indicator field in a DCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. A 3-bit PUCCH resource indicator field in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. The wireless device may transmit the HARQ-ACK information in a PUCCH resource indicated by the 3-bit PUCCH resource indicator field in the DCI.

FIG. 29 shows an example of mapping of PUCCH resource indication filed values to a PUCCH resource in a PUCCH resource set (e.g., with maximum 8 PUCCH resources). In an example, when the PUCCH resource indicator in the DCI (e.g., DCI format 1_0 or 1_1) is ‘000’, the wireless device may determine a PUCCH resource identified by a PUCCH resource identifier (e.g., pucch-Resourdceid) with a first value in the PUCCH resource list of the PUCCH resource set. When the PUCCH resource indicator in the DCI (e.g., DCI format 1_0 or 1_1) is ‘001’, the wireless device may determine a PUCCH resource identified by a PUCCH resource identifier (e.g., pucch-Resourdceid) with a second value in the PUCCH resource list of the PUCCH resource set, etc. Similarly, in order to transmit HARQ-ACK information, SR and/or CSI multiplexed in a PUCCH, the wireless device may determine the PUCCH resource based on at least the PUCCH resource indicator in a DCI (e.g., DCI format 1_0/1_1), from a list of PUCCH resources in a PUCCH resource set.

In an example, the wireless device may transmit one or more UCI bits via a PUCCH resource of an active uplink BWP of a PCell or a PUCCH secondary cell. Since at most one active uplink BWP in a cell is supported for a wireless device, the PUCCH resource indicated in the DCI is naturally a PUCCH resource on the active uplink BWP of the cell.

In an example, A gNB may indicate a UE transmit one or more SRS for channel quality estimation (e.g., CSI acquisition, or uplink beam management) to enable frequency-selective scheduling on the uplink. Transmission of SRS may be used for other purposes, such as to enhance power control or to support various startup functions for UEs not recently scheduled. Some examples include initial MCS (Modulation and Coding Scheme) selection, initial power control for data transmissions, timing advance, and frequency semi-selective scheduling.

In an example, a gNB may indicate a UE to transmit at least one of three types of SRS: periodic SRS transmission (type 0); aperiodic SRS transmission (type 1); semi-persistent SRS transmission. for the periodic SRS transmission, subframes in which SRSs may be transmitted may be indicated by cell-specific broadcast signaling, and/or UE-specific signaling.

FIG. 30A shows an example of periodic SRS transmission. Periodicity of the periodic SRS transmission may be a value from as often as once every 2 ms to as infrequently as once every 160 ms. A UE may transmit SRSs in SC-FDMA or OFDM symbols (e.g., last 1-3 symbols in a subframe) in the configured subframes. FIG. 30B shows an example of aperiodic SRS transmission. A UE may transmit SRS aperiodically in response to receiving a DCI indicating the aperiodic SRS transmission. FIG. 30C shows an example of SP SRS transmission. In an example, a UE may receive configuration parameters of SP SRS transmission. The configuration parameters may comprise at least one of: a periodicity of the SP SRS transmission; a time/frequency radio resource; cyclic shift parameters; and/or other radio parameters (e.g., bandwidth, frequency hopping, transmission comb and offset, frequency-domain position). The UE may transmit the SP SRS in response to receiving a first MAC CE activating the SP SRS. The UE may repeat the SP SRS transmission with the periodicity until receiving a second MAC CE deactivating the SP SRS. The UE may deactivate the SP SRS and stop the SP SRS transmission in response to receiving the second MAC CE deactivating the SP SRS.

FIG. 31 shows an example a beam failure recovery request (BFRQ) procedure. A wireless device may receive one or more RRC messages comprising BFRQ parameters. The wireless device may detect at least one beam failure according to at least one of the BFRQ parameters. The wireless device may start a first timer in response to detecting the at least one beam failure. The first timer may be used to determine how long the wireless device may find a candidate beam and may be referred to as a beam failure recovery timer (e.g., beamFailureRecoveryTimer). The wireless device may select a beam in response to detecting the at least one beam failure. The wireless device may transmit at least a first BFRQ signal to a gNB in response to selecting the beam. The wireless device may start a response window in response to transmitting the at least first BFRQ signal. In an example, the response window may be a second timer with a value configured by the gNB. When the response window is running, the wireless device may monitor a PDCCH in a first coreset. The first coreset may be associated with the BFRQ procedure. In an example, the wireless device may monitor the PDCCH in the first coreset in response to or after transmitting the at least first BFRQ signal. The wireless device may receive a first DCI via the PDCCH in the first coreset when the response window is running. The wireless device may consider the BFRQ procedure successfully completed when receiving the first DCI via the PDCCH in the first coreset before the response window expires. The wireless device may stop the first timer and/or stop the response window in response to the BFRQ procedure successfully being completed.

In an example, when the response window expires and the wireless device does not receive the DCI, the wireless device may, before the first timer expires, perform one or more actions comprising at least one of: a BFRQ signal transmission; re-starting the response window; or monitoring the PDCCH. In an example, the wireless device may repeat the one or more actions until the BFRQ procedure successfully completes or the first timer expires.

In an example, when the first timer expires and the wireless device does not receive the DCI, the wireless device may declare (or indicate) a BFRQ procedure failure. In an example, when a number of transmissions of BFRQ signals is greater than a configured number, a wireless device may declare (or indicate) a BFRQ procedure failure. In an example, after a wireless device declares (or indicates) a BFRQ procedure failure, a wireless device may keep monitoring a PDCCH in a first coreset and may miss PDCCH detection in a normal coreset and the wireless device may lose a connection with the base station. In an example, the wireless device may unnecessarily initiate a random access procedure when the wireless device indicates a radio link failure in response to a BFRQ procedure failure.

In an example, as shown in FIG. 32, a base station may configure a candidate beam set for a wireless device. When the wireless device moves in a cell, two beams of the candidate beam set may be blocked (e.g., by buildings or moving train) for the wireless device. The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the candidate beam set due to, for example, beam blocking as shown in FIG. 32. More specifically, because of beam blocking, none of the RSs that each corresponds to a respective one of the candidate beams from the candidate beam set may have a receive quality (e.g., RSRP or SINR) greater than a configured threshold. As a result, no candidate beam from the candidate beam set may be selected. In an example, the physical layer of the wireless device may indicate to the MAC entity of the wireless device that no candidate beam is selected. The MAC entity of the wireless device may stop the beamFailureRecoveryTimer in response to receiving the indication of no candidate beam being selected and may initiate a contention-based BFRQ procedure or a random access procedure.

FIG. 33 illustrates an example embodiment of multiple candidate beam sets configuration for a beam failure recovery procedure. A base station may configure multiple candidate beam sets for a wireless device (e.g., via an RRC message). The multiple candidate beam sets may comprise two or more candidate beam sets. Each of the multiple candidate beam sets may comprise a set of RSs. In an example, one or more of the sets of RSs may comprise one or more CSI-RSs. In an example, one or more of the sets of RSs may comprise one or more SSBs. In an example, different candidate beam sets of the multiple candidate beam sets may comprise a same number of candidate beams or RSs. In an example, different candidate beam sets of the multiple candidate beam sets may comprise a different number of candidate beams or RSs. The base station may configure a monitoring priority for the wireless device (e.g., via an RRC message). In an example, the monitoring priority configuration may indicate an order in which the wireless device is to monitor the multiple candidate beam sets.

The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. The wireless device may determine a first candidate beam set from the multiple candidate beam sets according to (or based on) the monitoring priority. The wireless device may select a candidate beam from the first candidate beam set. In an example, when the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the first candidate beam set due to, for example, no RS from the first candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the first candidate beam set satisfying some other selection requirement). In an example, in response to the wireless device not selecting a candidate beam from the first candidate beam set, the wireless device may determine a second candidate beam set from the multiple candidate beam sets according to (or based on) the monitoring priority. The wireless device may select a candidate beam from the second candidate beam set. In an example, when the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the second candidate beam set due to, for example, no RS from the second candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the second candidate beam set satisfying some other selection requirement). In an example, in response to the wireless device not selecting a candidate beam from the second candidate beam set, the wireless device may determine a third candidate beam set from the multiple candidate beam sets according to (or based on) the monitoring priority. The wireless device may select a candidate beam from the third candidate beam set. In an example, when the wireless device does not select a candidate beam from any of the multiple candidate beam sets, the wireless device may initiate a contention-based BFRQ procedure or a random access procedure.

In an example, as shown in FIG. 33, a base station may configure three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) for a wireless device. In an example, one or more of the three candidate beam sets may comprise sixteen candidate beams (or some other number of candidate beams). The base station may configure a monitoring priority to the wireless device (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2) for the three candidate beam sets. The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. In an example, the wireless device may select a candidate beam from a first candidate beam set (e.g., candidate beam set 1) of the configured candidate beam sets. The first candidate beam set may be selected by the wireless device according to (or based on) the monitoring priority (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2). In an example, when the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam for performing a BFRQ procedure due to, for example, no RS from the first candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or due to no RS from the first candidate beam set satisfying some other selection requirement).

In response to the wireless device not selecting a candidate beam from the first candidate beam set, the wireless device may select a candidate beam from a second candidate beam set (e.g., candidate beam set 0) of the configured candidate beam sets. The wireless device may determine the second candidate beam set according to (or based on) the monitoring priority (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2). In an example, when the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam for performing a BFRQ procedure due to, for example, no RS from the second candidate beam set having a receive quality (e.g., RSRP or SINR) greater than the configured threshold (or due to no RS from the second candidate beam set satisfying some other selection requirement).

In response to the wireless device not selecting a candidate beam from the second candidate beam set, the wireless device may select a candidate beam from a third candidate beam set (e.g., candidate beam set 2) of the configured candidate beam sets. In an example, the wireless device may determine the third candidate beam set according to (or based on) the monitoring priority configuration (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2).

In an example, when the wireless device does not select a candidate beam from any of the three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) due to, for example, no RS from any of the three candidate beam sets having a receive quality greater than the configured threshold (or due to no RS from the three candidate beam sets satisfying some other selection requirement), the wireless device may initiate a contention-based BFRQ procedure or a random access procedure.

FIG. 34 illustrates an example of a beam failure recovery procedure for multiple candidate beam sets in accordance with embodiments of the present disclosure. In an example, a wireless device may report the wireless device's capability for multiple candidate beam set monitoring to a base station at time T0. The wireless device's capability for candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. In an example, the wireless device may receive one or more RRC messages from the base station at time T1. The one or more RRC messages may comprise configuration parameters of beam failure recovery of a cell. The configuration parameters may indicate a serving beam set, multiple candidate beam sets, and a monitoring priority configuration for the multiple candidate beam sets. The serving beam set may comprise one or more RSs. Each of the multiple candidate beam sets may comprise one or more RSs. The one or more RSs may comprise one or more CSI-RSs (or SSBs). The monitoring priority configuration may indicate an order in which the wireless device is to monitor the multiple candidate beam sets. The wireless device may detect a beam failure instance for the serving beam set at T2. The physical layer of the wireless device may indicate to a high layer (e.g., the MAC layer of the wireless device) a beam failure instance when the measured radio link quality (e.g., RSRP or SINR) of all corresponding RSs in the serving beam set are lower than a threshold.

The wireless device may determine, in response to the detecting the beam failure instance for the serving beam set, a first candidate beam set of the multiple candidate beam sets at T3 according to (or based on) the monitoring priority. The first candidate beam set may have higher monitoring priority than other candidate beam sets of the multiple candidate beam sets. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set at T4. The wireless device may transmit, in response to identifying a candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery at T5. In an example, the preamble associated with the candidate beam may be identified by a preamble index determined by the candidate beam. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set at T4, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery.

The wireless device may determine, in response to not identifying a candidate beam from the first candidate beam set at T4, a second candidate beam set of the multiple candidate beam sets based on the monitoring priority. The second candidate beam set may have a second monitoring priority (In other words, a lower monitoring priority than the first candidate beam set, but a higher monitoring priority than the remaining candidate beam sets) in the multiple candidate beam sets as determined based on the monitoring priority configuration. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying a candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery.

The wireless device may determine, in response to not identifying a candidate beam from the second candidate beam set, a third candidate beam set from the multiple candidate beam sets based on the monitoring priority. The third candidate beam set may have a third monitoring priority (In other words, a lower monitoring priority than the first and the second candidate beam sets, but a higher monitoring priority than the remaining candidate beam sets if exist) in the multiple candidate beam sets. The wireless device may monitor the third candidate beam set to identify a candidate beam from the third candidate beam set. The wireless device may transmit, in response to identifying a candidate beam from the third candidate beam set, a preamble associated with the candidate beam from the third candidate beam set for the beam failure recovery. In response to not identifying a candidate beam from the third candidate beam set, the wireless device may apply the same rule presented above of selecting a next highest priority candidate beam set from the remaining multiple candidate beam sets according to (or based on) the monitoring priority and continue the candidate beam identification procedure.

FIG. 35 illustrates an example of flow chart of a beam failure recovery procedure for multiple candidate beam sets configuration in accordance with embodiments of the present disclosure. A wireless device may report the wireless device's capability for multiple candidate beam set monitoring to a base station. The wireless device's capability for multiple candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. The wireless device may receive serving beam set configuration, multiple candidate beam set configurations, and monitoring priority configuration. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine a first candidate beam set according to (or based on) the monitoring priority. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the first candidate beam set, a preamble associated with the identified candidate beam from the first candidate beam set.

The wireless device may determine, in responding to not identifying the candidate beam from the first candidate beam set, a second candidate beam set according to (or based on) the monitoring priority. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the second candidate beam set, a preamble associated with the identified candidate beam from the second candidate beam set. The wireless device may monitor, in responding to not identifying the candidate beam from the second candidate beam set, one of the other candidate beam sets according to (or based on) the monitoring priority configuration. The wireless device may identify a candidate beam from the one of the other candidate beam sets according to the monitoring priority configuration. The wireless device may transmit, in responding to identifying the candidate beam from the one of the other candidate beam sets according to the monitoring priority configuration, a preamble associated with the identified candidate beam from the one of the other candidate beam sets. The wireless device may transmit a preamble for contention based random access procedure when the wireless device does not identify a candidate beam from any of the multiple candidate beam sets.

A wireless device may receive, from a base station, one or more messages comprising configuration parameters of a cell for beam failure recovery. The configuration parameters may indicate: a serving beam set, a plurality of candidate beam sets, and a monitoring priority for the plurality of candidate beam sets. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The wireless device may determine, in response to not identifying the candidate beam from the first candidate beam set, a second candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The first candidate beam set may have a higher monitoring priority than the second candidate beam set. Each of the plurality of candidate beam sets may comprise one or more reference signals. The one or more reference signals may comprise SS/PBCH block (SSB) or channel state information reference signal (CSI-RS). The detecting the beam failure instance may comprise detecting all corresponding resource configurations in the serving beam set are worse than a threshold. The all corresponding resource configurations in the serving beam set may be reference signals of the serving beam set. The plurality of candidate beam sets may comprise multiple candidate beam sets for candidate beam monitoring. The monitoring priority configuration may indicate a monitoring priority order for the plurality of candidate beam sets. The preamble, associated with the candidate beam, may be identified by a preamble index determined by the candidate beam. The preamble resources may comprise preamble index, preamble frequency domain transmission resources, or preamble time domain transmission resources.

FIG. 36 illustrates an example of multiple candidate beam set configurations for a beam failure recovery procedure in accordance with embodiments of the present disclosure. A base station may configure multiple candidate beam sets for a wireless device (e.g., via an RRC message). The multiple candidate beam sets may comprise two or more candidate beam sets. Each of the multiple candidate beam sets may comprise a set of RSs. One or more of the sets of RSs may comprise one or more CSI-RSs. One or more of the sets of RSs may comprise one or more SSBs. Different candidate beam sets of the multiple candidate beam sets may comprise a same number of candidate beams or RSs. Different candidate beam sets of the multiple candidate beam sets may comprise a different number of candidate beams or RSs. The base station may configure multiple monitoring priorities to the wireless device (e.g., via an RRC message). The multiple monitoring priorities may indicate multiple orders in which the wireless device is to monitor the multiple candidate beam sets.

The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. The wireless device may receive a downlink control information (DCI) indicating a monitoring priority of the multiple monitoring priorities. The monitoring priority may indicate a monitoring priority order in which the wireless device is to monitor the multiple candidate beam sets. The wireless device may determine a first candidate beam set from the multiple candidate beam sets according to (or based on) the monitoring priority. The wireless device may select a candidate beam from the first candidate beam set. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the first candidate beam set due to, for example, no RS from the first candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the first candidate beam set satisfying some other selection requirement). In response to the wireless device not selecting a candidate beam from the first candidate beam set, the wireless device may determine a second candidate beam set from the multiple candidate beam sets according to (or based on) the monitoring priority. The wireless device may select a candidate beam from the second candidate beam set. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the second candidate beam set due to, for example, no RS from the second candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the second candidate beam set satisfying some other selection requirement). In response to the wireless device not selecting a candidate beam from the second candidate beam set, the wireless device may determine a third candidate beam set from the multiple candidate beam sets according to (based on) the monitoring priority. The wireless device may select a candidate beam from the third candidate beam set. When the wireless device does not select a candidate beam from any of the multiple candidate beam sets, the wireless device may initiate a contention-based BFRQ procedure or a random access procedure.

In an example, as shown in FIG. 36, a base station may configure three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) for a wireless device via an RRC message. One or more of the three candidate beam sets may comprise sixteen candidate beams or some other number of candidate beams. The base station may configure multiple monitoring priorities to the wireless device (e.g., (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0), (0, 1, 2), and (0, 2, 1)) for the three candidate beam sets via an RRC message. The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. The wireless device may receive a downlink control information indicating a monitoring priority configuration (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2) of the multiple monitoring priorities. The wireless device may select a candidate beam from a first candidate beam set (e.g., candidate beam set 1) of the configured candidate beam sets. The first candidate beam set may be selected according to the monitoring priority (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2). When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam for performing a BFRQ procedure due to, for example, no RS from the first candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or due to no RS from the first candidate beam set satisfying some other selection requirements).

In response to the wireless device not selecting a candidate beam from the first candidate beam set, the wireless device may select a candidate beam from a second candidate beam set (e.g., candidate beam set 0) of the configured candidate beam sets. The second candidate beam set may be selected according to the monitoring priority (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2). When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam for performing a BFRQ procedure due to, for example, no RS from the second candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or due to no RS from the second candidate beam set satisfying some other selection requirements). In response to the wireless device not selecting a candidate beam from the second candidate beam set, the wireless device may select a candidate beam from a third candidate beam set (e.g., candidate beam set 2) of the configured candidate beam sets. The third candidate beam set may be selected according to the monitoring priority (e.g., in order: candidate beam set 1, candidate beam set 0, and candidate beam set 2). When the wireless device does not select a candidate beam from any of the three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) due to, for example, no RS from any of the three candidate beam sets having a receive quality greater than the configured threshold (or due to no RS from the three candidate beam sets satisfying some other selection requirement), the wireless device may initiate a contention-based BFRQ procedure, or a random access procedure.

FIG. 37 illustrates an example of a beam failure recovery procedure for multiple candidate beam set configurations in accordance with embodiments of the present disclosure. A wireless device may report the wireless device's capability for multiple candidate beam set monitoring to a base station at time T0. The wireless device's capability for candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. The wireless device may receive one or more RRC messages from the base station at time T1. The one or more RRC messages may comprise configuration parameters of beam failure recovery of a cell. The configuration parameters may indicate a serving beam set, multiple candidate beam sets, and multiple monitoring priorities for the multiple candidate beam sets. The serving beam set may comprise one or more RSs. Each of the multiple candidate beam sets may comprise one or more RSs. The one or more RSs may comprise one or more CSI-RSs (or SSBs). The multiple monitoring priorities for the multiple candidate beam sets may indicate multiple orders in which the wireless device is to monitor the multiple candidate beam sets. The wireless device may receive a downlink control information indicating a monitoring priority of the multiple monitoring priorities at T2.

The wireless device may detect a beam failure instance for the serving beam set at T3. The physical layer of the wireless device may indicate to a high layer (e.g., the MAC layer of the wireless device) a beam failure instance when the measured radio link quality (e.g., RSRP or SINR) of all corresponding RSs in the serving beam set are lower than a threshold. The wireless device may determine, in response to the detecting the beam failure instance for the serving beam set, a first candidate beam set of the multiple candidate beam sets at T4 according to (or based on) the monitoring priority. The first candidate beam set may have higher monitoring priority than other candidate beam sets of the multiple candidate beam sets as determined based on the monitoring priority. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set at T5. The wireless device may transmit, in response to identifying a candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery at T6. The preamble associated with the candidate beam may be identified by a preamble index determined by the candidate beam. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set at T5, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery.

The wireless device may determine, in response to not identifying the candidate beam from the first candidate beam set at T5, a second candidate beam set of the multiple candidate beam sets based on the monitoring priority. The second candidate beam set may have a second monitoring priority (In other words, a lower monitoring priority than the first candidate beam set, but a higher monitoring priority than the remaining candidate beam sets) in the multiple candidate beam sets as determined based on the monitoring priority. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying a candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery.

The wireless device may determine, in response to not identifying a candidate beam from the second candidate beam set, a third candidate beam set from the multiple candidate beam sets based on the monitoring priority. The third candidate beam set may have a third monitoring priority in the multiple the candidate beam sets. The wireless device may monitor the third candidate beam set to identify a candidate beam from the third candidate beam set. In response to not identifying a candidate beam from the third candidate beam set, the wireless device may apply the same rule presented above of selecting a next highest priority candidate beam set from the remaining multiple candidate beam sets according to the monitoring priority and continue the candidate beam identification procedure.

FIG. 38 illustrates an example flow chart of beam failure recovery procedure for multiple candidate beam set configurations in accordance with embodiments of the present disclosure. A wireless device may report the wireless device's capability for multiple candidate beam sets monitoring to a base station. The wireless device's capability for candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. The wireless device may receive a serving beam set configuration, multiple candidate beam set configurations, and multiple monitoring priorities configuration. The wireless device may receive a downlink control information indicating a monitoring priority of the multiple monitoring priorities. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine a first candidate beam set according to the monitoring priority. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the first candidate beam set, a preamble associated with the identified candidate beam from the first candidate beam set.

The wireless device may determine, in responding to not identifying the candidate beam from the first candidate beam set, a second candidate beam set according to (or based on) the monitoring priority. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the second candidate beam set, a preamble associated with the identified candidate beam from the second candidate beam set. The wireless device may monitor, in responding to not identifying the candidate beam from the second candidate beam set, one of the other candidate beam sets according to the monitoring priority. The wireless device may identify a candidate beam from the one of the other candidate beam sets according to (or based on) the monitoring priority. The wireless device may transmit, in responding to identifying the candidate beam from the one of the other candidate beam sets according to the monitoring priority, a preamble associated with the identified candidate beam from the one of the other candidate beam sets. The wireless device may transmit a preamble for contention based random access procedure when the wireless device does not identify a candidate beam from the multiple candidate beam sets.

A wireless device may receive, from a base station, one or more messages comprising configuration parameters of a cell for beam failure recovery. The configuration parameters may indicate: a serving beam set, a plurality of candidate beam sets, and a plurality of monitoring priorities for the plurality of candidate beam sets. The wireless device may receive a downlink control information indicating a monitoring priority of the plurality of monitoring priorities. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The wireless device may determine, in response to not identifying the candidate beam from the first candidate beam set, a second candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The first candidate beam set may have a higher monitoring priority than the second candidate beam set. Each of the plurality of candidate beam sets may comprise one or more reference signals. The one or more reference signals may comprise on or more SS/PBCH blocks (SSBs) or channel state information reference signals (CSI-RSs). The detecting the beam failure instance may comprise detecting all corresponding resource configurations in the serving beam set are worse than a threshold. The all corresponding resource configurations in the serving beam set may be reference signals of the serving beam set. The plurality of candidate beam sets may comprise multiple candidate beam sets for candidate beam monitoring. The monitoring priority may indicate a monitoring priority order for the plurality of candidate beam sets. The preamble, associated with the candidate beam, may be identified by a preamble index determined by the candidate beam. The preamble resources may comprise preamble index, preamble frequency domain transmission resources, or preamble time domain transmission resources.

FIG. 39 illustrates an example of multiple candidate beam set configurations for a beam failure recovery procedure in accordance with embodiments of the present disclosure. A base station may configure multiple candidate beam sets for a wireless device (e.g. via an RRC message). The multiple candidate beam sets may comprise two or more candidate beam sets. Each of the multiple candidate beam sets may comprise a set of RSs. One or more of the sets of RSs may comprise one or more CSI-RSs. One or more of the sets of RSs may comprise one or more SSBs. Different candidate beam sets of the multiple candidate beam sets may comprise a same number of candidate beams or RSs. Different candidate beam sets of the multiple candidate beam sets may comprise a different number of candidate beams or RSs. The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. The wireless device may measure a channel quality for each of the multiple candidate beam sets. The wireless device may determine a first candidate beam set from the multiple candidate beam sets according to (or based on) the channel quality measurement. The wireless device may determine the first candidate beam set with a best channel quality from the multiple candidate beam sets. The best channel quality may comprise having a highest SINR, and/or RSRP, and/or a lowest BLER for PDCCH based on reference signal measurement of the candidate beam set.

The wireless device may select a candidate beam from the first candidate beam set. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the first candidate beam set due to, for example, no RS from the first candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the first candidate beam set satisfying some other selection requirement). In response to the wireless device not selecting a candidate beam from the first candidate beam set, the wireless device may determine a second candidate beam set from the multiple candidate beam sets according to (or based on) the channel quality measurement. The wireless device may select a candidate beam from the second candidate beam set. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the second candidate beam set due to, for example, no RS from the second candidate beam set having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or no RS from the second candidate beam set satisfying some other selection requirement). In response to the wireless device not selecting a candidate beam from the second candidate beam set, the wireless device may determine a third candidate beam set from the multiple candidate beam sets according to the channel quality measurement. The wireless device may select a candidate beam from the third candidate beam set. The first candidate beam set may have a better channel quality than the second candidate beam set. The second candidate beam set may have a better channel quality than the third candidate beam set. The wireless device may apply the same rule to select the candidate beam from other remaining candidate beams sets of the multiple candidate beam sets according to (or based on) the channel quality measurement. When the wireless device does not select a candidate beam from any of the multiple candidate beam sets, the wireless device may initiate a contention-based BFRQ procedure or a random access procedure.

In an example, as shown in FIG. 39, a base station may configure three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) for a wireless device (e.g., via an RRC message). One or more of the three candidate beam sets may comprise sixteen candidate beams or some other number of candidate beams. The wireless device may measure a channel quality with an order from high to low as: candidate beam set 1, candidate beam set 0, and candidate beam set 2 for the three candidate beam sets. The wireless device may start a beam failure recovery timer (e.g., beamFailureRecoveryTimer) when detecting a number of contiguous beam failures. The wireless device may select a candidate beam from candidate beam set 1 according to (or based on) the channel quality order. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from candidate beam set 1 due to, for example, no RS from the candidate beam set 1 having a receive quality (e.g., RSRP or SINR) greater than a configured threshold (or due to no RS from the candidate beam set 1 satisfying some other selection requirement). The wireless device may select a candidate beam from the candidate beam set 0 according to (or based on) the channel quality order. When the beamFailureRecoveryTimer is running, the wireless device may not select a candidate beam from the candidate beam set 0 due to, for example, no RS from candidate beam set 0 having a receive quality (e.g., RSRP or SINR) greater than the configured threshold (or due to no RS from the candidate beam set 0 satisfying some other selection requirement). In response to the wireless device not selecting a candidate beam from the candidate beam set 0, the wireless device may select a candidate beam from candidate beam set 2 according to (or based on) the channel quality order. When the wireless device does not select a candidate beam from any of the three candidate beam sets (e.g., candidate beam set 0, candidate beam set 1 and candidate beam set 2) due to, for example, no RS from any of the three candidate beam sets having a receive quality greater than the configured threshold, the wireless device may initiate a contention-based BFRQ procedure, or a random access procedure.

FIG. 40 illustrates an example of a beam failure recovery procedure for multiple candidate beam set configurations in accordance with embodiments of the present disclosure. A wireless device may report the wireless device's capability for multiple candidate beam set monitoring to a base station at time T0. The wireless device's capability for candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. The wireless device may receive one or more RRC messages from the base station at time T1. The one or more RRC messages may comprise configuration parameters of beam failure recovery on a cell. The configuration parameters may indicate a serving beam set, and multiple candidate beam sets. The serving beam set may comprise one or more RSs. Each of the multiple candidate beam sets may comprise one or more RSs. The one or more RSs may comprise one or more CSI-RSs or SSBs. The wireless device may detect a beam failure instance for the serving beam set at T2. The physical layer of the wireless device may indicate to a high layer (e.g., the MAC layer of the wireless device) a beam failure instance when the measured radio link quality (e.g., RSRP or SINR) of all corresponding RSs in the serving beam set are lower than a threshold.

The wireless device may determine, in response to the detecting the beam failure instance for the serving beam set, a first candidate beam set of the multiple candidate beam sets at T3 according to channel quality measurement for the multiple candidate beam sets. The first candidate beam set may have a better channel quality than other candidate beam sets of the multiple candidate beam sets as determined based on the channel quality measurement. The wireless device may determine the first candidate beam set according to (or based on) the channel quality measurement. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set at T4. The wireless device may transmit, in response to identifying the candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery at T5. The preamble associated with the candidate beam may be identified by a preamble index determined by the candidate beam. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery.

The wireless device may determine, in response to not identifying the candidate beam from the first candidate beam set, a second candidate beam set of the multiple candidate beam sets based on the channel quality measurement. The second candidate beam set may have a worse channel quality than the first candidate beam set. The second candidate beam set may have a second channel quality (In other words, a worse channel quality than the first candidate beam set and a better channel quality than the remaining candidate beam sets) in the multiple candidate beam sets. The wireless device may determine the second candidate beam set according to the channel quality measurement. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure. The wireless device may transmit the preamble for the contention based random access procedure for the beam failure recovery. The wireless device may determine, in response to not identifying the candidate beam from the second candidate beam set, a third candidate beam set from the multiple candidate beam sets. The third candidate beam set may have a third channel quality in the plurality of the candidate beam sets. The wireless device may monitor the third candidate beam set to identify a candidate beam from the third candidate beam set. In response to not identifying a candidate beam from the third candidate beam set, the wireless device may apply the same rule presented above of selecting a next candidate beam set with highest channel quality from the remaining candidate beam sets of the multiple candidate beam sets according to the channel quality measurement and continue the candidate beam identification procedure.

FIG. 41 illustrates an example flow chart of a beam failure recovery procedure for multiple candidate beam set configurations in accordance with embodiments of the present disclosure. A wireless device may report the wireless device's capability for multiple candidate beam set monitoring to a base station. The wireless device's capability for candidate beam set monitoring may indicate the wireless device's capability to monitor a number of RS sets or candidate beam sets. The wireless device may receive serving beam set configuration, and multiple candidate beam set configurations. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine a first candidate beam set according to a channel quality measurement. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the first candidate beam set, a preamble associated with the identified candidate beam from the first candidate beam set.

The wireless device may determine, in responding to not identifying the candidate beam from the first candidate beam set, a second candidate beam set according to the channel quality measurement. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in responding to identifying the candidate beam from the second candidate beam set, a preamble associated with the identified candidate beam from the second candidate beam set. The wireless device may monitor, in responding to not identifying the candidate beam from the second candidate beam set, one of the other candidate beam sets according to the channel quality measurement. The wireless device may identify a candidate beam from the one of the other candidate beam sets according to the channel quality measurement. The wireless device may transmit, in responding to identifying the candidate beam from the one of the other candidate beam sets according to the channel quality measurement, a preamble associated with the identified candidate beam from the one of the other candidate beam sets. The wireless device may transmit a preamble for contention based random access procedure when the wireless device does not identify a candidate beam from any of the multiple candidate beam sets.

A wireless device may receive, from a base station, one or more messages comprising configuration parameters of a cell for beam failure recovery. The configuration parameters may indicate: a serving beam set, and a plurality of candidate beam sets. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on a channel quality measurement. The wireless device may monitor the first candidate beam set to identify a candidate beam from the first candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the first candidate beam set, a preamble associated with the candidate beam for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the first candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The wireless device may determine, in response to not identifying the candidate beam from the first candidate beam set, a second candidate beam set of the plurality of candidate beam sets based on the channel quality measurement. The wireless device may monitor the second candidate beam set to identify a candidate beam from the second candidate beam set. The wireless device may transmit, in response to identifying the candidate beam from the second candidate beam set, a preamble associated with the candidate beam from the second candidate beam set for the beam failure recovery. The wireless device may select, in response to not identifying the candidate beam from the second candidate beam set, a preamble for a contention based random access procedure and transmit the preamble for the beam failure recovery. The first candidate beam set may have a better channel quality than the second candidate beam set. Each of the plurality of candidate beam sets may comprise one or more reference signals. The one or more reference signals may comprise one or more SS/PBCH blocks (SSBs) or channel state information reference signals (CSI-RSs). The detecting the beam failure instance may comprise detecting all corresponding resource configurations in the serving beam set are worse than a threshold. The all corresponding resource configurations in the serving beam set may be reference signals of the serving beam set. The plurality of candidate beam sets may comprise multiple candidate beam sets for candidate beam monitoring. The preamble, associated with the candidate beam, may be identified by a preamble index determined by the candidate beam. The preamble resources may comprise preamble index, preamble frequency domain transmission resources or preamble time domain transmission resources.

According to various embodiments, a device such as, for example, a wireless device, off-network wireless device, a base station, and/or the like, may comprise one or more processors and memory. The memory may store instructions that, when executed by the one or more processors, cause the device to perform a series of actions. Embodiments of example actions are illustrated in the accompanying figures and specification. Features from various embodiments may be combined to create yet further embodiments.

FIG. 42 is a flow diagram as per an aspect of an example embodiment of the present disclosure. At 4210, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s). The configuration parameter(s) may indicate a monitoring priority of a plurality of candidate beam sets. At 4220, the wireless device may detect a beam failure instance of a serving beam set. At 4230, the wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. At 4240, the wireless device may select a candidate beam from the first candidate beam set. At 4250, the wireless device may transmit a preamble associated with the candidate beam for beam failure recovery.

FIG. 43 is a flow diagram as per an aspect of an example embodiment of the present disclosure. At 4310, a base station may transmit one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s). The configuration parameter(s) may indicate a monitoring priority of a plurality of candidate beam sets. At 4320, the base station may transmit one or more reference signals of a serving beam set. At 4330, the base station may transmit one or more reference signals of the plurality of candidate beam sets. At 4340, the base station may receive a preamble associated with a candidate beam for beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on the monitoring priority.

According to an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a monitoring priority of the plurality of candidate beam sets. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may select a candidate beam from the first candidate beam set. The wireless device may transmit a preamble associated with the candidate beam for the beam failure recovery.

According to an example embodiment, the wireless device may determine, in response to not selecting the candidate beam from the first candidate beam set, a second preamble for a contention based random access procedure. The wireless device may transmit the second preamble for the beam failure recovery. According to an example embodiment, the wireless device may determine, in response to not selecting the candidate beam from the first candidate beam set, a second candidate beam set of the plurality of candidate beam sets based on the monitoring priority. According to an example embodiment, the wireless device may monitor the second candidate beam set to select a second candidate beam from the second candidate beam set. According to an example embodiment, the first candidate beam set may have a higher monitoring priority than the second candidate beam set. According to an example embodiment, the wireless device may transmit, in response to selecting the second candidate beam from the second candidate beam set, a third preamble associated with the second candidate beam from the second candidate beam set for the beam failure recovery. According to an example embodiment, the wireless device may determine, in response to not selecting the second candidate beam from the second candidate beam set, a fourth preamble for a contention based random access procedure. The wireless device may transmit the fourth preamble for the beam failure recovery. According to an example embodiment, each of the plurality of candidate beam sets may comprise one or more reference signals. According to an example embodiment, the one or more reference signals may comprise one or more synchronization signal/physical broadcast channel blocks (SSBs). According to an example embodiment, the one or more reference signals may comprise one or more channel state information reference signals (CSI-RSs). According to an example embodiment, the detecting the beam failure instance may comprise detecting corresponding resources in the serving beam set are worse than a threshold. According to an example embodiment, the corresponding resources in the serving beam set may comprise reference signals of the serving beam set. According to an example embodiment, the plurality of candidate beam sets may comprise multiple candidate beam sets for candidate beam monitoring. According to an example embodiment, the monitoring priority may indicate a monitoring priority order of the plurality of candidate beam sets. According to an example embodiment, the preamble, associated with the candidate beam may be identified by a preamble resource associated with the candidate beam. According to an example embodiment, the preamble resource may comprise a preamble index. The preamble resource may comprise a transmission resource in frequency domain for the preamble. The preamble resource may comprise a transmission resource in time domain for the preamble. According to an example embodiment, the serving beam set may comprise one or more reference signals. According to an example embodiment, the one or more reference signals may comprise one or more synchronization signal/physical broadcast channel blocks (SSBs). The one or more reference signals may comprise one or more channel state information reference signals (CSI-RSs). According to an example embodiment, the configuration parameters may indicate an association between the preamble and with the candidate beam.

According to an example embodiment, a base station may transmit, to a wireless device, one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a monitoring priority of the plurality of candidate beam sets. The base station may transmit one or more reference signals of the serving beam set. The base station may transmit one or more reference signals of the plurality of candidate beam sets. The base station may receive a preamble associated with a candidate beam for the beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on the monitoring priority.

According to an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a monitoring priority of the plurality of candidate beam sets. The wireless device may detect a beam failure instance of a serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may select a candidate beam from the first candidate beam set. The wireless device may transmit a preamble associated with the candidate beam for the beam failure recovery.

According to an example embodiment, a base station may transmit, to a wireless device, one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a monitoring priority of the plurality of candidate beam sets. The base station may transmit one or more reference signals of a serving beam set. The base station may transmit one or more reference signals of the plurality of candidate beam sets. The base station may receive a preamble associated with a candidate beam for the beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on the monitoring priority.

According to an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a monitoring priority of a plurality of candidate beam sets. The wireless device may detect a beam failure instance of a serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the monitoring priority. The wireless device may select a candidate beam from the first candidate beam set. The wireless device may transmit a preamble associated with the candidate beam for the beam failure recovery.

According to an example embodiment, a base station may transmit, to a wireless device, one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a monitoring priority of a plurality of candidate beam sets. The base station may transmit one or more reference signals of a serving beam set. The base station may transmit one or more reference signals of the plurality of candidate beam sets. The base station may receive a preamble associated with a candidate beam for the beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on the monitoring priority.

According to an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a plurality of monitoring priorities of the plurality of candidate beam sets. The wireless device may receive a downlink control information indicating one of the plurality of monitoring priorities. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on the one of the plurality of monitoring priorities. The wireless device may select a candidate beam from the first candidate beam set. The wireless device may transmit a preamble associated with the candidate beam for the beam failure recovery.

According to an example embodiment, a base station may transmit, to a wireless device, one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The configuration parameter(s) may indicate a plurality of monitoring priorities of the plurality of candidate beam sets. The base station may transmit one or more reference signals of the serving beam set. The base station may transmit one or more reference signals of the plurality of candidate beam sets. The base station may transmit a downlink control information indicating one of the plurality of monitoring priorities. The base station may receive a preamble associated with a candidate beam for the beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on the one of the plurality of monitoring priorities.

According to an example embodiment, a wireless device may receive one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The wireless device may detect a beam failure instance of the serving beam set. The wireless device may determine, in response to the detecting, a first candidate beam set of the plurality of candidate beam sets based on a channel quality measurement. The wireless device may select a candidate beam from the first candidate beam set. The wireless device may transmit a preamble associated with the candidate beam for the beam failure recovery.

According to an example embodiment, a base station may transmit, to a wireless device, one or more radio resource control (RRC) messages. The RRC message(s) may comprise configuration parameter(s) of a cell for beam failure recovery. The configuration parameter(s) may indicate a serving beam set. The configuration parameter(s) may indicate a plurality of candidate beam sets. The base station may transmit one or more reference signals of the serving beam set. The base station may transmit one or more reference signals of the plurality of candidate beam sets. The base station may receive a preamble associated with a candidate beam for the beam failure recovery. The candidate beam may be selected from a first candidate beam set determined based on a channel quality measurement.

Embodiments may be configured to operate as needed. The disclosed mechanism may be performed when certain criteria are met, for example, in a wireless device, a base station, a radio environment, a network, a combination of the above, and/or the like. Example criteria may be based, at least in part, on for example, wireless device or network node configurations, traffic load, initial system set up, packet sizes, traffic characteristics, a combination of the above, and/or the like. When the one or more criteria are met, various example embodiments may be applied. Therefore, it may be possible to implement example embodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wireless devices and/or base stations may support multiple technologies, and/or multiple releases of the same technology. Wireless devices may have some specific capability(ies) depending on wireless device category and/or capability(ies). A base station may comprise multiple sectors. When this disclosure refers to a base station communicating with a plurality of wireless devices, this disclosure may refer to a subset of the total wireless devices in a coverage area. This disclosure may refer to, for example, a plurality of wireless devices of a given LTE or 5G release with a given capability and in a given sector of the base station. The plurality of wireless devices in this disclosure may refer to a selected plurality of wireless devices, and/or a subset of total wireless devices in a coverage area which perform according to disclosed methods, and/or the like. There may be a plurality of base stations or a plurality of wireless devices in a coverage area that may not comply with the disclosed methods, for example, because those wireless devices or base stations perform based on older releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to be interpreted as “at least one” and “one or more.” Similarly, any term that ends with the suffix “(s)” is to be interpreted as “at least one” and “one or more.” In this disclosure, the term “may” is to be interpreted as “may, for example.” In other words, the term “may” is indicative that the phrase following the term “may” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

If A and B are sets and every element of A is also an element of B, A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B={cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on” (or equally “based at least on”) is indicative that the phrase following the term “based on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “in response to” (or equally “in response at least to”) is indicative that the phrase following the phrase “in response to” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “depending on” (or equally “depending at least to”) is indicative that the phrase following the phrase “depending on” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments. The phrase “employing/using” (or equally “employing/using at least”) is indicative that the phrase following the phrase “employing/using” is an example of one of a multitude of suitable possibilities that may, or may not, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether the device is in an operational or non-operational state. Configured may also refer to specific settings in a device that effect the operational characteristics of the device whether the device is in an operational or non-operational state. In other words, the hardware, software, firmware, registers, memory values, and/or the like may be “configured” within a device, whether the device is in an operational or nonoperational state, to provide the device with specific characteristics. Terms such as “a control message to cause in a device” may mean that a control message has parameters that may be used to configure specific characteristics or may be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

In this disclosure, various embodiments are disclosed. Limitations, features, and/or elements from the disclosed example embodiments may be combined to create further embodiments within the scope of the disclosure.

In this disclosure, parameters (or equally called, fields, or Information elements: IEs) may comprise one or more information objects, and an information object may comprise one or more other objects. For example, if parameter (IE) N comprises parameter (IE) M, and parameter (IE) M comprises parameter (IE) K, and parameter (IE) K comprises parameter (information element) J. Then, for example, N comprises K, and N comprises J. In an example embodiment, when one or more messages comprise a plurality of parameters, it implies that a parameter in the plurality of parameters is in at least one of the one or more messages, but does not have to be in each of the one or more messages.

Furthermore, many features presented above are described as being optional through the use of “may” or the use of parentheses. For the sake of brevity and legibility, the present disclosure does not explicitly recite each and every permutation that may be obtained by choosing from the set of optional features. However, the present disclosure is to be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features may be embodied in seven different ways, namely with just one of the three possible features, with any two of the three possible features or with all three of the three possible features.

Many of the elements described in the disclosed embodiments may be implemented as modules. A module is defined here as an element that performs a defined function and has a defined interface to other elements. The modules described in this disclosure may be implemented in hardware, software in combination with hardware, firmware, wetware (i.e. hardware with a biological element) or a combination thereof, all of which may be behaviorally equivalent. For example, modules may be implemented as a software routine written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab or the like) or a modeling/simulation program such as Simulink, Stateflow, GNU Octave, or LabVIEWMathScript. Additionally, it may be possible to implement modules using physical hardware that incorporates discrete or programmable analog, digital and/or quantum hardware. Examples of programmable hardware comprise: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers and microprocessors are programmed using languages such as assembly, C, C++ or the like. FPGAs, ASICs and CPLDs are often programmed using hardware description languages (HDL) such as VHSIC hardware description language (VHDL) or Verilog that configure connections between internal hardware modules with lesser functionality on a programmable device. The above mentioned technologies are often used in combination to achieve the result of a functional module.

The disclosure of this patent document incorporates material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, for the limited purposes required by law, but otherwise reserves all copyright rights whatsoever.

While various embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the scope. In fact, after reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement alternative embodiments. Thus, the present embodiments should not be limited by any of the above described exemplary embodiments.

In addition, it should be understood that any figures which highlight the functionality and advantages, are presented for example purposes only. The disclosed architecture is sufficiently flexible and configurable, such that it may be utilized in ways other than that shown. For example, the actions listed in any flowchart may be re-ordered or only optionally used in some embodiments.

Further, the purpose of the Abstract of the Disclosure is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract of the Disclosure is not intended to be limiting as to the scope in any way.

Finally, it is the applicant's intent that only claims that include the express language “means for” or “step for” be interpreted under 35 U.S.C. 112. Claims that do not expressly include the phrase “means for” or “step for” are not to be interpreted under 35 U.S.C. 112. 

What is claimed is:
 1. A method performed by a wireless device, comprising: receiving, from a base station, one or more radio resource control messages comprising configuration parameters of a cell for beam failure recovery, wherein the configuration parameters indicate: a serving beam set; a plurality of candidate beam sets, wherein each candidate beam set, of the plurality of candidate beam sets, comprises a plurality of reference signals (RSs); a priority order to select a candidate beam set from the plurality of candidate beam sets; and an association between a preamble and one or more RSs of the plurality of RSs; detecting a beam failure of the serving beam set; selecting, in response to the detecting, a first candidate beam set from the plurality of candidate beam sets based on the priority order; monitoring the first candidate beam set; and in response to determining, based on the monitoring, that a first candidate RS, of a plurality of candidate RSs associated with the first candidate beam set, has a channel quality better than a threshold: selecting the first candidate RS; and transmitting the preamble associated with the first candidate RS of the one or more RSs for the beam failure recovery.
 2. The method of claim 1, further comprising: selecting, in response to the detecting and based on the priority order, a second candidate beam set from the plurality of candidate beam sets before selection of the first candidate beam set; and determining, based on monitoring the second candidate beam set, not to select a second RS from a plurality of second RSs associated with the second candidate beam set, wherein the selecting of the first candidate beam set is in response to the determining not to select the second RS.
 3. The method of claim 2, wherein the priority order indicates that the second candidate beam set has a higher priority than the first candidate beam set.
 4. The method of claim 1, wherein the plurality of first candidate RSs comprise: one or more synchronization signal physical broadcast channel blocks; or one or more channel state information reference signals (CSI-RSs).
 5. The method of claim 1, wherein the detecting the beam failure comprises detecting that the channel quality of reference signals in the serving beam set is less than the threshold.
 6. The method of claim 1, wherein each candidate beam set of the plurality of candidate beam sets comprises multiple candidate beams.
 7. The method of claim 1, wherein the preamble is identified by a preamble resource associated with the first candidate RS, and wherein the preamble resource comprises at least one of: a preamble index, a transmission resource in frequency domain for the preamble, and a transmission resource in time domain for the preamble.
 8. A wireless device comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, cause the wireless device to: receive, from a base station, one or more radio resource control messages comprising configuration parameters of a cell for beam failure recovery, wherein the configuration parameters indicate: a serving beam set; a plurality of candidate beam sets, wherein each candidate beam set, of the plurality of candidate beam sets, comprises a plurality of reference signals (RSs); a priority order to select a candidate beam set from the plurality of candidate beam sets; and an association between a preamble and one or more RSs of the plurality of RSs; detect a beam failure of the serving beam set; select, in response to detection of the beam failure of the serving beam set, a first candidate beam set from the plurality of candidate beam sets based on the priority order; monitor the first candidate beam set; and in response to determining, based on monitoring the first candidate beam set, that a first candidate RS, of a plurality of candidate RSs associated with the first candidate beam set, has a channel quality better than a threshold: select the first candidate RS; and transmit the preamble associated with the first candidate RS of the one or more RSs for the beam failure recovery.
 9. A system comprising: a base station comprising: one or more first processors; and first memory storing first instructions that, when executed by the one or more first processors, cause the base station to transmit one or more radio resource control messages comprising configuration parameters of a cell for beam failure recovery, wherein the configuration parameters indicate: a serving beam set; a plurality of candidate beam sets, wherein each candidate beam set, of the plurality of candidate beam sets, comprises a plurality of reference signals (RSs); a priority order to select a candidate beam set from the plurality of candidate beam sets; and an association between a preamble and one or more RSs of the plurality of RSs; and a wireless device comprising: one or more second processors; and second memory storing second instructions that, when executed by the one or more second processors, cause the wireless device to: receive the one or more radio resource control messages; detect a beam failure of the serving beam set; select, in response to detection of the beam failure of the serving beam set, a first candidate beam set from the plurality of candidate beam sets based on the priority order; monitor the first candidate beam set; and in response to determining, based on monitoring the first candidate beam set, that a first candidate RS, of a plurality of candidate RSs associated with the first candidate beam set, has a channel quality better than a threshold: select the first candidate RS; and transmit the preamble associated with the first candidate RS of the one or more RSs for the beam failure recovery.
 10. The wireless device of claim 8, wherein the instructions further cause the wireless device to: select, in response to the detection of the beam failure and based on the priority order, a second candidate beam set from the plurality of candidate beam sets before selection of the first candidate beam set; and determine, based on monitoring the second candidate beam set, not to select a second RS from a plurality of second RSs associated with the second candidate beam set, wherein the selection of the first candidate beam set is in response to determining not to select the second RS.
 11. The wireless device of claim 8, wherein the plurality of first candidate RSs comprise: one or more synchronization signal physical broadcast channel blocks; or one or more channel state information reference signals (CSI-RSs).
 12. The wireless device of claim 8, wherein the instructions, when executed by the one or more processors, further cause the wireless device to detect that the channel quality of reference signals in the serving beam set is less than the threshold.
 13. The wireless device of claim 8, wherein each candidate beam set of the plurality of candidate beam sets comprises multiple candidate beams.
 14. The wireless device of claim 8, wherein the preamble is identified by a preamble resource associated with the first candidate RS, and wherein the preamble resource comprises at least one of: a preamble index, a transmission resource in frequency domain for the preamble, and a transmission resource in time domain for the preamble. 